Drop CI cargo-clippy check, can't run on Gitea

The Reviewdog tool hits GitHub API endpoints that don't have an
equivalent on Gitea.

.gitea/workflows/check.yml

@@ -34,31 +34,6 @@ jobs:
           components: rustfmt
       - name: cargo fmt --check
         run: cargo fmt --check
-  clippy:
-    runs-on: ubuntu-latest
-    name: ${{ matrix.toolchain }} / clippy
-    permissions:
-      contents: read
-      checks: write
-    strategy:
-      fail-fast: false
-      matrix:
-        # Get early warning of new lints which are regularly introduced in beta channels.
-        toolchain: [stable, beta]
-    steps:
-      - uses: actions/checkout@v4
-        with:
-          submodules: true
-      - name: Install ${{ matrix.toolchain }}
-        uses: dtolnay/rust-toolchain@master
-        with:
-          toolchain: ${{ matrix.toolchain }}
-          components: clippy
-      - name: cargo clippy
-        uses: giraffate/clippy-action@v1
-        with:
-          reporter: 'github-pr-check'
-          github_token: ${{ secrets.GITHUB_TOKEN }}
   semver:
     runs-on: ubuntu-latest
     name: semver