CI: Use branch-versioned cargo throughout (#13411)

(cherry picked from commit 66c3c6c2b3)

Co-authored-by: Trent Nelson <trent@solana.com>

storage-bigtable/build-proto/build.sh

@@ -3,8 +3,10 @@
 set -ex
 cd "$(dirname "$0")"
 
+cargo="$(readlink -f "../../cargo")"
+
 if [[ ! -d googleapis ]]; then
   git clone https://github.com/googleapis/googleapis.git
 fi
 
-exec cargo run
+exec "$cargo" run