List caches not in specified branch list

[tpak]

Describe the feature or problem you’d like to solve

Return a list of caches not associated to a branch or branches specified by the user.

Proposed solution

-x <string> Exclude branches from result set

ex:
gh actions-cache list --order asc --sort last-used -x staging,development,main

this would return all caches except those on the 3 branches staging,development,main

This would allow a user to find all non-critical branch caches and clean them up. Combined with a date filter, as requested in #51 would make cache query and cleanup more flexible. This new flag could be specified in conjunction with either the list or delete commands.

[tpak]

a special use case could also exclude all protected branches in a repository

ex:
-x protected

the reserved keyword "protected" would find and eliminate all protected branches from the list or delete command