[PR Workflow] Automatic ARM sign-off for TypeSpec-based PRs

[rkmanda]

We have now reached a state with the set of linter rule automation that have been put in place where we can start enabling more self-serve scenarios and simplify the PR review process for RP owners.

The first step towards this is to automatically sign-off the PRs that are raised for open api specs that are generated from Typespec. After reviewing a bunch of PRs that were created for Typespec based PRs, we have reached a conclusion that we can automatically sign-off these PRs without requiring a manual review.

Criteria to be met for an automatic sign-off

• No errors reported by the swagger linter rules (Swagger Lintdiff and Swagger Lintdiff (RPaaS))
• Open API spec is generated from TypeSpec
  • note by @konrad-jamrozik: this depends on [PR Workflow] Add TypeSpec label if appropriate files are changed #7353

Mechanism to indicate sign-off

• Add a new label when the above criteria is met, label name suggestion - "ARMAutomaticSignOff".
• The automated merging criteria needs to take this label into account. The existence of one of ARMSignedOff or ARMAutomaticSignOff labels will be used as a way to determine whether the PR was signed off by ARM.

Prerequisites before this automation is put in place in production

• One final linter rule update to production by end of November that has some important fixes

Edit by kojamroz:

Related doc in ARM wiki:

• Pull Request 9459836: API review best practice and self attestation checklist for Typespec based PRs

[konrad-jamrozik]

@rkmanda by this:

No errors reported by the linter rules

Do you mean all linters? These:

• Swagger LintDiff
• Swagger LintDiff(RPaaS)
• TypeSpec Validation
• Swagger PtettierCheck
• Swagger SpellCheck
• Swagger SemanticValidation
• Swagger ModelValidation
• Swagger Breaking Change
• Breaking Change(Cross-Version)

[rkmanda]

Sorry I meant the Swagger Lintdiff and Swagger Lintdiff (RPaaS) linter rules @konrad-jamrozik

[konrad-jamrozik]

Note: we will also have to update the https://aka.ms/azsdk/pr-diagram and automated PR comments appropriately.