Fix stale cache issue in content-deploy workflow

Include source files in cache key to ensure rebuilds when
code changes on main branch. The workflow runs from content
branch, so it needs the fix here too.

Author: hakimjonas

.github/workflows/content-deploy.yml

@@ -44,7 +44,9 @@ jobs:
             ~/.cargo/registry/cache/
             ~/.cargo/git/db/
             target/
-          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
+          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock', 'src/**/*.rs', 'Cargo.toml') }}
+          restore-keys: |
+            ${{ runner.os }}-cargo-
 
       - name: Install Typst CLI
         uses: baptiste0928/cargo-install@v3