internal/ci: simplify and improve clearing of all cache entries

actions/gh-actions-cache is now deprecated in favor of the new
built-in `gh cache` command, which luckily includes flags to select
a repository, delete all of its cache entries, and succeed if there
is nothing to delete at all.

Tested manually on a repository of mine that this works as intended.
Now that the script is much simpler, we don't need `set -x` either.

Signed-off-by: Daniel Martí <[email protected]>
Change-Id: I09d6044d69584bf4590cf51a407e87fdbc3264df
Reviewed-on: https://review.gerrithub.io/c/cue-lang/cue/+/1211352
TryBot-Result: CUEcueckoo <[email protected]>
Reviewed-by: Paul Jolly <[email protected]>
Unity-Result: CUE porcuepine <[email protected]>

Author: mvdan

.github/workflows/evict_caches.yaml

@@ -48,20 +48,11 @@ jobs:
           false
       - name: Delete caches
         run: |-
-          set -x
-
           echo ${{ secrets.CUECKOO_GITHUB_PAT }} | gh auth login --with-token
-          gh extension install actions/gh-actions-cache
           for i in https://github.com/cue-lang/cue https://github.com/cue-lang/cue-trybot
           do
           	echo "Evicting caches for $i"
-          	cd $(mktemp -d)
-          	git init -b initialbranch
-          	git remote add origin $i
-          	for j in $(gh actions-cache list -L 100 | grep refs/ | awk '{print $1}')
-          	do
-          	   gh actions-cache delete --confirm $j
-          	done
+          	gh cache delete --repo $i --all --succeed-on-no-caches
           done
       - name: Trigger workflow runs to repopulate caches
         run: |-

internal/ci/base/gerrithub.cue

@@ -248,20 +248,11 @@ evictCaches: bashWorkflow & {
 				githubactions.#Step & {
 					name: "Delete caches"
 					run:  """
-						set -x
-
 						echo ${{ secrets.\(botGitHubUserTokenSecretsKey) }} | gh auth login --with-token
-						gh extension install actions/gh-actions-cache
 						for i in \(githubRepositoryURL) \(trybotRepositoryURL)
 						do
 							echo "Evicting caches for $i"
-							cd $(mktemp -d)
-							git init -b initialbranch
-							git remote add origin $i
-							for j in $(gh actions-cache list -L 100 | grep refs/ | awk '{print $1}')
-							do
-							   gh actions-cache delete --confirm $j
-							done
+							gh cache delete --repo $i --all --succeed-on-no-caches
 						done
 						"""
 				},