ci: Track released artifacts for EO 14028 compliance. (#709)

Author: hessjcg

.kokoro/release/release.cfg

@@ -1 +1,10 @@
-# Format: //devtools/kokoro/config/proto/build.proto
+# Format: //devtools/kokoro/config/proto/build.proto
+
+# Save artifacts for EO 14028
+action {
+  define_artifacts {
+    regex: "**/dist/*.tar.gz"
+    regex: "**/dist/*.whl"
+    strip_prefix: "github/cloud-sql-python-connector"
+  }
+}