feat(bazel): add bzlmod integrity gen function (#12797)

Co-authored-by: Carlo Sala <carlosalag@protonmail.com>

plugins/bazel/bazel.plugin.zsh

@@ -3,3 +3,7 @@ alias bzb='bazel build'
 alias bzt='bazel test'
 alias bzr='bazel run'
 alias bzq='bazel query'
+
+sri-hash() {
+    openssl dgst -sha256 -binary $1 | openssl base64 -A | sed 's/^/sha256-/'
+}