ci: fix `Validate Conventional Commit Title` action

[davidmurdoch]

The Validate Conventional Commit Title action was only running when the PR was opened (and if the title or base are edited, or the PR was closed then re-opened). It was not when the branch had a new commit added; in that case, the previous run's status would just be completely ignored by GitHub.

Adding "synchronize" fixes it (as the installation instructions specify: https://github.com/amannn/action-semantic-pull-request?tab=readme-ov-file#installation)

note: we probably don't need "reopened", but I don't know why that was added in the first place so I'm not removing it.

I tested this here: https://github.com/MetaMask/metamask-extension/pull/24355/commits

Check out the statuses for each commit (hover over the red X). The action ran on the first commit, as expected, and it did not ran on the next two, but the last commit added synchronize (just like in this PR), and it ran again.

[github-actions[bot]]

CLA Signature Action: All authors have signed the CLA. You may need to manually re-run the blocking PR check if it doesn't pass in a few minutes.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 67.37%. Comparing base (4a1853c) to head (72ce899).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## develop #24356 +/- ## ======================================== Coverage 67.37% 67.37% ======================================== Files 1278 1278 Lines 49881 49881 Branches 12944 12944 ======================================== Hits 33605 33605 Misses 16276 16276 ```

:umbrella: View full report in Codecov by Sentry.
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[metamaskbot]

Builds ready [72ce899]

• builds: chrome, firefox
• builds (beta): chrome
• builds (flask): chrome, firefox
• builds (MMI): chrome, firefox
• builds (test): chrome, firefox
• builds (test-flask): chrome, firefox
• build viz: Build System
• mv3: Background Module Init Stats
• mv3: UI Init Stats
• mv3: Module Load Stats
• mv3: Bundle Size Stats
• mv2: E2e Actions Stats
• code coverage: Report
• storybook: Storybook
• typescript migration: Dashboard
• all artifacts
• bundle viz:

  • background: 0, 1, 2, 3, 4, 5, 6
  • common: 0, 1, 2, 3, 4, 5, 6, 7, 8
  • content-script: 0
  • ui: 0, 1, 10, 2, 3, 4, 5, 6, 7, 8, 9

Page Load Metrics (289 ± 342 ms)

Platform	Page	Metric	Min (ms)	Max (ms)	Average (ms)	StandardDeviation (ms)	MarginOfError (ms)
Chrome	Home	firstPaint	55	133	70	20	9
		domContentLoaded	8	15	10	2	1
		load	45	2518	289	712	342
		domInteractive	8	15	10	2	1

Bundle size diffs

• background: 0 Bytes (0.00%)
• ui: 0 Bytes (0.00%)
• common: 0 Bytes (0.00%)