Create Pulumi templates for managing repo settings in MeltanoLabs

Following from this discussion. We would like to be able to manage repo settings (including permissions) centrally and via IAC. As Pulumi is our IAC language of choice, it makes sense to start there.

Related to:

• Give meltano engineering team write access to all repos MeltanoLabs/Meta#21

Overview spec:

• New repo in MeltanoLabs with Pulumi project containing IAC for all Taps/Targets in MeltanoLabs org.

• Since the repos already exist, we'd need to first import or get resources and then apply changes.
• We'd declare our preferred settings for each repo, including common settings like allow_merge_commit, allow_auto_merge, and other configuration details.
• We could define groups of differently-configured repos as needed; not all repos would need to have identical configurations - but likely we could manage all repos with 2-4 total configsets.

Start with the linked discussion #26 and related issue #21, then define the new MeltanoLabs repository as a Pulumi project. Identify how existing Taps/Targets repositories will be imported or read, and document the 2–4 configuration sets and settings they should enforce. Done means the existing repositories and their permissions are centrally managed through the declared Pulumi configuration.