Fix Integration Workflow

[Hydrocharged]

This makes a few changes to how the integration workflow is handled:

• main is now merged into this PR before testing. Previously, we would just use the PR as-is, which created a situation where the main branch included changes that the PR had not yet merged in. This created an issue as Dolt and DoltgreSQL would expect some changes to be present that were not yet merged into the PR, causing compilation errors. By merging main, we bypass this. In addition, the workflow will automatically pass if a merge conflict is detected. I think this is fine, since conflicts must be resolved before the PR can be merged anyway. This does mean that some errors may not be caught for as long as merge conflicts against main exist.
• We only pulled comments, and the PR description does not count as a comment. This made it seem a bit inconsistent with how PR detection was handled. This has now been added, and we're now doing a basic string search instead of using a JSON parser, as concatenating the comments and description does not result in a valid JSON object.
• Workflow should automatically run when a comment is added, modified, or deleted. This was already supposed to happen, but the event structure differed between a comment and push in a subtle way, causing the workflow to immediately error and for the UI to continue displaying the previous run. This made it seem as though the workflow did not respond to comment updates.
• Additional logging messages have been added, so it's easier to debug if something goes wrong in the future.

[fulghum]

LGTM! 🚢