Update release-plz.yml

Make the git commit attempt not return exit code 1 if empty

Author: tjtelan

.github/workflows/release-plz.yml

@@ -77,6 +77,6 @@ jobs:
             gh pr checkout $pr_number
             # change "echo" with your commands
             git add .
-            git commit -m "ci: Update msrv and/or readme"
+            git commit -m "ci: Update msrv and/or readme" | true
             git push
-          fi
+          fi