*: unpin rules_go/gazelle

We unpin these now that Gazelle 0.21.0 is out. This release also changes
runfile pathnames for go_binary, so we have to fix up the test_boot.sh
script that hardcodes a path.

This also pulls in a new protobuf version, that we have to let in with
its imperfections that nogo rightfully complains about.

Test Plan: machinery change, current tests cover this

X-Origin-Diff: phab/D538
GitOrigin-RevId: ad83d7868608b6883a891d127a6fbaf28f8aa14a
diff --git a/core/scripts/test_boot.sh b/core/scripts/test_boot.sh
index 4a5dead..36ab079 100755
--- a/core/scripts/test_boot.sh
+++ b/core/scripts/test_boot.sh
@@ -7,7 +7,7 @@
 # have to worry about cross-compilation or varying build environments.
 #
 # (see https://github.com/bazelbuild/bazel/blob/master/tools/bash/runfiles/runfiles.bash)
-set kubectl_path "external/io_k8s_kubernetes/cmd/kubectl/linux_amd64_pure_stripped/kubectl"
+set kubectl_path "external/io_k8s_kubernetes/cmd/kubectl/kubectl_/kubectl"
 
 set timeout 120