Update rust-cache GHA in deploy workflow

This action was way outdated, produced a lot of warnings and didn't seem to work
anymore.

Author: flip1995

.github/workflows/deploy.yml

@@ -52,7 +52,9 @@ jobs:
       run: cargo generate-lockfile
 
     - name: Cache
-      uses: Swatinem/[email protected]
+      uses: Swatinem/[email protected]
+      with:
+        save-if: ${{ github.ref == 'refs/heads/master' }}
 
     - name: cargo collect-metadata
       run: cargo collect-metadata