improve GitHub workflows to only run when necessary

There is no reason to run clippy or `cargo test` when we do not change
Rust code (as in some PRs that improve documentation or example
scripts).

There is no reason to run `cargo deny` if our dependencies did not
change (which we can track by just looking at `Cargo.lock`).

Finally, we added an `cargo_update` action, that will run monthly, and a
`doc-build` action that will run everytime a documentation file changes,
to ensure the docs can always be built.

Author: LGFae

.github/workflows/clippy.yml

@@ -0,0 +1,43 @@
+name: Clippy
+
+on:
+  pull_request:
+    paths:
+      - '**.rs'
+      - '**Cargo.toml'
+  merge_group:
+  push:
+    branches:
+      - main
+    paths:
+      - '**.rs'
+      - '**Cargo.toml'
+
+env:
+  CARGO_TERM_COLOR: always
+  SCCACHE_GHA_ENABLED: "true"
+  RUSTC_WRAPPER: "sccache"
+
+jobs:
+  clippy:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v5
+      - uses: mozilla-actions/[email protected]
+      - uses: dtolnay/rust-toolchain@stable
+        with:
+          components: clippy
+      - run: sudo apt install -y libwayland-dev wayland-protocols
+      - run: cargo clippy --version
+      - run: cargo clippy --workspace --locked --tests
+
+  fmt:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v5
+      - uses: mozilla-actions/[email protected]
+      - uses: dtolnay/rust-toolchain@stable
+        with:
+          components: rustfmt
+      - run: cargo fmt --version
+      - run: cargo fmt --all --check

.github/workflows/dependencies.yml

@@ -1,7 +1,15 @@
 name: Dependencies
 
 on:
-  workflow_call:
+  pull_request:
+    paths:
+      - '**Cargo.lock'
+  merge_group:
+  push:
+    branches:
+      - main
+    paths:
+      - '**Cargo.lock'
 
 env:
   CARGO_TERM_COLOR: always
@@ -12,7 +20,7 @@ jobs:
   advisories:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: mozilla-actions/[email protected]
       - uses: dtolnay/rust-toolchain@stable
       - uses: taiki-e/install-action@cargo-deny
@@ -21,7 +29,7 @@ jobs:
   bans:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: mozilla-actions/[email protected]
       - uses: dtolnay/rust-toolchain@stable
       - uses: taiki-e/install-action@cargo-deny
@@ -30,7 +38,7 @@ jobs:
   licences:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: mozilla-actions/[email protected]
       - uses: dtolnay/rust-toolchain@stable
       - uses: taiki-e/install-action@cargo-deny
@@ -39,7 +47,7 @@ jobs:
   sources:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: mozilla-actions/[email protected]
       - uses: dtolnay/rust-toolchain@stable
       - uses: taiki-e/install-action@cargo-deny

.github/workflows/doc.yml

@@ -0,0 +1,20 @@
+name: Doc
+
+on:
+  pull_request:
+    paths:
+      - '**.scd'
+  merge_group:
+  push:
+    branches:
+      - main
+    paths:
+      - '**.scd'
+
+jobs:
+  doc-build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v5
+      - run: sudo apt install -y scdoc
+      - run: ./doc/gen.sh

.github/workflows/test.yml

@@ -1,31 +1,33 @@
 name: Test
 
 on:
-  workflow_call:
+  pull_request:
+    paths:
+      - '**.rs'
+      - '**Cargo.toml'
+  merge_group:
+  push:
+    branches:
+      - main
+    paths:
+      - '**.rs'
+      - '**Cargo.toml'
 
 env:
   CARGO_TERM_COLOR: always
   SCCACHE_GHA_ENABLED: "true"
   RUSTC_WRAPPER: "sccache"
 
 jobs:
-  nightly:
+  test:
     runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        toolchain: [stable, nightly]
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: mozilla-actions/[email protected]
-      - uses: dtolnay/rust-toolchain@nightly
-      - uses: taiki-e/install-action@cargo-nextest
-      - run: sudo apt install -y libwayland-dev wayland-protocols
-      - run: cargo build --workspace --locked --verbose
-      - run: cargo nextest run --workspace --locked
-
-  stable:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - uses: mozilla-actions/[email protected]
-      - uses: dtolnay/rust-toolchain@stable
+      - uses: dtolnay/rust-toolchain@${{ strategy.toolchain }}
       - uses: taiki-e/install-action@cargo-nextest
       - run: sudo apt install -y libwayland-dev wayland-protocols
       - run: cargo build --workspace --locked --verbose
@@ -34,7 +36,7 @@ jobs:
   msrv:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: mozilla-actions/[email protected]
       - uses: SebRollen/[email protected]
         id: msrv

.github/workflows/update-dependencies.yml

@@ -0,0 +1,18 @@
+name: update-dependencies
+on:
+  schedule:
+    - cron: '0 0 1 * *' # Run monthly
+
+env:
+  CARGO_TERM_COLOR: always
+  SCCACHE_GHA_ENABLED: "true"
+  RUSTC_WRAPPER: "sccache"
+
+jobs:
+  cargo_update:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v5
+      - uses: moonrepo/setup-rust@v1
+      - run: cargo update
+      - uses: peter-evans/create-pull-request@v7

.github/workflows/update-flake-lock.yml

@@ -1,6 +1,5 @@
 name: update-flake-lock
 on:
-  workflow_dispatch: # allows manual triggering
   schedule:
     - cron: '0 0 1 * *' # Run monthly
   push:
@@ -12,12 +11,9 @@ jobs:
   lockfile:
     runs-on: ubuntu-latest
     steps:
-      - name: Checkout repository
-        uses: actions/checkout@v4
-      - name: Install Nix
-        uses: cachix/install-nix-action@v27
+      - uses: actions/checkout@v5
+      - uses: cachix/install-nix-action@v27
         with:
           extra_nix_config: |
             access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
-      - name: Update flake.lock
-        uses: DeterminateSystems/update-flake-lock@v21
+      - uses: DeterminateSystems/update-flake-lock@v21