Use the correct `ref` arg for fetching GitLab repo contents (#7351) #15898

Job	Run time
Lint	1m 2s
ci (bundler, bundler1, 2, 0, bundler)	4m 37s
ci (bundler, bundler1, 2, 1, bundler)	3m 25s
ci (bundler, bundler2, 2, 0, bundler)	5m 26s
ci (bundler, bundler2, 2, 1, bundler)	3m 21s
ci (cargo, cargo, cargo)	2m 50s
ci (common, common, common)	1m 54s
ci (composer, composer, 2, 0, composer)	3m 31s
ci (composer, composer, 2, 1, composer)	4m 49s
ci (docker, docker, docker)	1m 27s
ci (elm, elm, elm)	1m 43s
ci (git_submodules, git_submodules, gitsubmodule)	1m 22s
ci (github_actions, github_actions, github-actions)	1m 48s
ci (go_modules, go_module, 2, 0, gomod)	2m 47s
ci (go_modules, go_module, 2, 1, gomod)	6m 33s
ci (gradle, gradle, gradle)	1m 24s
ci (hex, hex, 2, 0, mix)	6m 27s
ci (hex, hex, 2, 1, mix)	7m 14s
ci (maven, maven, maven)	1m 44s
ci (npm_and_yarn, npm_and_yarn, 3, 0, npm)	4m 18s
ci (npm_and_yarn, npm_and_yarn, 3, 1, npm)	10m 47s
ci (npm_and_yarn, npm_and_yarn, 3, 2, npm)	6m 1s
ci (nuget, nuget, nuget)	1m 42s
ci (pub, pub, 2, 0, pub)	7m 54s
ci (pub, pub, 2, 1, pub)	6m 29s
ci (python, python, 2, 0, pip)	28m 7s
ci (python, python, 2, 1, pip)	24m 13s
ci (python, python_slow, 2, 0, pip)	21m 27s
ci (python, python_slow, 2, 1, pip)	21m 23s
ci (swift, swift, 2, 0, swift)	5m 50s
ci (swift, swift, 2, 1, swift)	2m 6s
ci (terraform, terraform, terraform)	3m 55s
Updater	3m 22s
	3h 30m 58s

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