[CI] Also set CACHE_GCS_BUCKET in premerge buildbot containers

Otherwise the cache_lit_timing_files.py script will not work.

Author: boomanaiden154

zorg/buildbot/builders/annotated/premerge/dispatch_job.py

@@ -106,6 +106,7 @@ def start_build_linux(commit_sha: str, bucket_name: str, k8s_client) -> str:
         "export CXX=clang++",
         "export POSTCOMMIT_CI=1",
         f"export SCCACHE_GCS_BUCKET={bucket_name}",
+        f"export CACHE_GCS_BUCKET={bucket_name}",
         "export SCCACHE_GCS_RW_MODE=READ_WRITE",
         "export SCCACHE_IDLE_TIMEOUT=0",
         "sccache --start-server",
@@ -130,6 +131,7 @@ def start_build_windows(commit_sha: str, bucket_name: str, k8s_client):
         f"git checkout {commit_sha}",
         "export POSTCOMMIT_CI=1",
         f"export SCCACHE_GCS_BUCKET={bucket_name}",
+        f"export CACHE_GCS_BUCKET={bucket_name}",
         "export SCCACHE_GCS_RW_MODE=READ_WRITE",
         "export SCCACHE_IDLE_TIMEOUT=0",
         "sccache --start-server",