chore: Use colons instead of em-dashes in workflow names

[jat255]

The em-dash separators from #378 render poorly in the Actions UI. Quotes are required since the values now contain colons.

[github-actions]

Preview deployed to Connect (dogfood.team.pct.posit.it): https://dogfood.team.pct.posit.it/connect/#/apps/d7a36cae-8f27-448b-a478-61b81fbe3942/draft/371682

Deployed from commit 94232d4.

[github-actions]

Preview root: https://posit-dev.github.io/commons/pr-379/

Python site preview: https://posit-dev.github.io/commons/pr-379/py/

Built from the latest commit on this branch. The R links in it point at the published R site, which no pull request rebuilds.

[github-actions]

Preview deployed to Connect (connect.staging.pct.posit.it): https://connect.staging.pct.posit.it/connect/#/apps/ad662e1b-5048-4acc-9ad7-f9478c92274e/draft/2995

Deployed from commit 94232d4.

[github-actions]

Cleaned up 1 preview bundle(s) on https://dogfood.team.pct.posit.it: 371682

[github-actions]

Cleaned up 1 preview bundle(s) on https://connect.staging.pct.posit.it: 2995