Update CI rules

Author: khvzak

.github/workflows/main.yml

@@ -28,7 +28,7 @@ jobs:
         - target: wasm32-unknown-emscripten
           os: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@main
     - uses: dtolnay/rust-toolchain@stable
       with:
         target: ${{ matrix.target }}
@@ -70,7 +70,7 @@ jobs:
         - os: windows-latest
           target: x86_64-pc-windows-msvc
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@main
     - uses: dtolnay/rust-toolchain@stable
       with:
         target: ${{ matrix.target }}
@@ -84,8 +84,8 @@ jobs:
     runs-on: ubuntu-latest
     needs: build
     steps:
-    - uses: actions/checkout@v4
-    - uses: dtolnay/rust-toolchain@nightly
+    - uses: actions/checkout@main
+    - uses: dtolnay/rust-toolchain@stable
       with:
         target: wasm32-unknown-emscripten
     - name: Install emscripten
@@ -103,7 +103,7 @@ jobs:
     name: Rustfmt
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@main
     - uses: dtolnay/rust-toolchain@stable
       with:
         components: rustfmt