Revert "ci: tmp pin nightly version (#6435)"

This reverts commit dee1fae.

Author: DaniPopes

.github/workflows/book.yml

@@ -58,8 +58,6 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@nightly
-        with:
-          toolchain: nightly-2024-02-03
       - name: Install mdbook
         run: |
           mkdir mdbook

.github/workflows/dependencies.yml

@@ -33,8 +33,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@nightly
-        with:
-          toolchain: nightly-2024-02-03
+
       - name: cargo update
         # Remove first line that always just says "Updating crates.io index"
         run: cargo update --color never 2>&1 | sed '/crates.io index/d' | tee -a cargo_update.log

.github/workflows/lint.yml

@@ -24,8 +24,6 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@clippy
-        with:
-          toolchain: nightly-2024-02-03
       - uses: Swatinem/rust-cache@v2
         with:
           cache-on-failure: true
@@ -41,8 +39,6 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@clippy
-        with:
-          toolchain: nightly-2024-02-03
       - uses: Swatinem/rust-cache@v2
         with:
           cache-on-failure: true
@@ -92,8 +88,6 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@nightly
-        with:
-          toolchain: nightly-2024-02-03
       - uses: Swatinem/rust-cache@v2
         with:
           cache-on-failure: true
@@ -113,7 +107,6 @@ jobs:
       - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@nightly
         with:
-          toolchain: nightly-2024-02-03
           components: rustfmt
       - run: cargo fmt --all --check
 

.github/workflows/sanity.yml

@@ -20,8 +20,6 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@nightly
-        with:
-          toolchain: nightly-2024-02-03
       - uses: taiki-e/install-action@cargo-udeps
       - name: Check for unused dependencies
         run: cargo udeps --lib --features "jemalloc,${{ matrix.network }}"