build: use different runner image so as to have access to git binary

.github/workflows/diregapic.yaml

diff --git a/.github/workflows/diregapic.yaml b/.github/workflows/diregapic.yaml
index 3ff6d10..703e84e 100644
--- a/.github/workflows/diregapic.yaml
+++ b/.github/workflows/diregapic.yaml
@@ -9,7 +9,7 @@
   regenerate-compute:
     if: github.repository == 'googleapis/googleapis'
     runs-on: ubuntu-latest
-    container: gcr.io/gapic-images/googleapis:prod
+    container: gcr.io/gapic-images/googleapis:20250505
     strategy:
       fail-fast: false
       matrix: