ci: remove Mergify auto-merge for version bump PRs

[gsarantid]

Summary

Removes the auto-merge version bump PRs Mergify rule from .mergify.yml so GitHub's native merge queue owns merging into main.

Rationale

GitHub's native merge queue is enforced on main. Mergify's merge: action performs a direct merge, which bypasses the queue — GitHub then rejects it with "GitHub refused to merge the pull request". This is the second time this pattern has bitten:

• chore: migrate to GitHub native merge queue #5871 migrated most Mergify rules from queue: to merge: when moving to GitHub's native queue.
• ci: fix auto-merge version bump PRs rule to use merge instead of queue #6678 (b035bd1f) did the same for the version-bump rule after it started dequeuing with "Repository rule violations found: Changes must be made through the merge queue" — the same error we're seeing now on Bump cloudbeat version to 9.5.0 #7225.

The merge: action was a stopgap that worked only until the ruleset actually enforced the queue. Now that it does, Mergify shouldn't be attempting the merge at all — GitHub's native auto-merge (gh pr merge --auto --squash or the UI checkbox) and "Merge when ready" flow already handle queued merges cleanly, so this rule is redundant and actively harmful.

Scope

Narrow — only removes the auto-merge version bump PRs rule. The auto-merge Renovate PRs (line 16) and mergify-housekeeping (line 93) rules use the same merge: action pattern and are latent versions of the same bug — they'll be handled in follow-ups once they actually surface, to keep this PR focused.

Test plan

• .mergify.yml still parses as valid YAML
• Structural schema check: 14 remaining rules, all with valid name/conditions/actions, only known Mergify actions used (assign, backport, close, comment, label, merge, review)
• Fork-based smoke test: [fork smoke test] ci: remove Mergify auto-merge for version bump PRs gsarantid/cloudbeat#4 — git plumbing verified end-to-end. Note: Mergify is not installed on the fork, so behavioral verification against Mergify's service was not possible without an interactive OAuth install; the change is a self-contained YAML block removal with no cross-references so behavioral risk is minimal.
• No cross-references — Mergify rules don't reference each other by name, so removing this rule cannot affect any other rule.

Made with Cursor

[mergify]

This pull request does not have a backport label. Could you fix it @gsarantid? 🙏
To fixup this pull request, you need to add the backport labels for the needed
branches, such as:

• backport-v./d./d./d is the label to automatically backport to the 8./d branch. /d is the digit
• backport-active-all is the label that automatically backports to all active branches.
• backport-active-8 is the label that automatically backports to all active minor branches for the 8 major.
• backport-active-9 is the label that automatically backports to all active minor branches for the 9 major.

[gurevichdmitry]

LGTM

[mergify]

Tick the box to add this pull request to the merge queue (same as @mergifyio queue).

• Queue this pull request