[CI] Set environment var to throw exception when compiling unsafe gencode

This sets an environment variable to let the build fail when compiling with potentially unsafe protobuf code. Generated code prior to protobuf version 3.22 might throw an error now.

This is necesarry because the unsafe code was blocked by newer protobuf versions, but is now allowed back to compile with protobuf version 4.33.0.

Ref: https://github.com/protocolbuffers/protobuf/releases/tag/v33.0

Author: TobiGr

.github/workflows/ci.yml

@@ -59,7 +59,8 @@ jobs:
           ./gradlew check \
             -Dorg.gradle.welcome=never \
             --stacktrace \
-            -Ddownloader=$downloader_type
+            -Ddownloader=$downloader_type \
+            -Dcom.google.protobuf.error_on_unsafe_pre22_gencode
 
       - name: Upload test reports when failure occurs
         uses: actions/upload-artifact@v5