Replace the save button with the button component with a loading state viarant

[jldec]

The initial Beta implementation (PR #7337) of Dotfiles support uses a simple text input for users to configure the URL of their dotfiles repository.

This issue defines a repo-selection UI to make this process more friendly by allowing users to search for and select their dotfiles repo without leaving the dashboard.

Proposed specifiication

• Select any repo under your personal account (users must clone first if they want to use a 3rd-party dotfiles repo).
• Choose from repos from any existing git provider integration.
• Don't offer to add new git provider integrations inside the repo selection flow, instead link to the main integrations setttings page (leaving the flow).

[PatMyron]

Would love it to default if a repo is named dotfiles:
#7337 (comment)

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[gtsiolis]

The UX around setting and managing .dotfiles could definitely benefit from another iteration. ➿

Posting below some early designs from a past exploration:

Disabled .dotfiles	Enabled .dotfiles

Preferences (Unset)	Preferences (Select)

[gtsiolis]

This could probably now re-use the repository selection dropdown from #15287 (comment). We would only need an action to clear the selection. Cc @svenefftinge

BEFORE	AFTER

[gtsiolis]

Now that we have a button component with a loading variant (see relevant PR Cc @selfcontained) we could drop and replace that there as the next iteration.

[gtsiolis]

Re-purposed this issue to something simpler, like replacing the save button with the button with a loading state variant.