Fix extension watcher infinite loop

[isaacroldan]

WHY are these changes introduced?

I recently introduced some changes in the extensions watcher to unify them into a single one.

However, I made a last minute change: from watching only inside src to watching in any folder. I didn't test that properly and it obviously breaks everything because we shouldn't watch in folders like dist or node_modules

WHAT is this pull request doing?

• Only watch for files inside the src folder
• Ignore test files (we don't need to upload a new draft if you change the tests)

How to test your changes?

• run dev in an app with different extension types and try to make changes in files inside src/dist/node_modules and also test file. Only actual source files should trigger a re-build

Post-release steps

Measuring impact

How do we know this change was effective? Please choose one:

• n/a - this doesn't need measurement, e.g. a linting rule or a bug-fix
• Existing analytics will cater for this addition
• PR includes analytics changes to measure impact

Checklist

• I've considered possible cross-platform impacts (Mac, Linux, Windows)
• I've considered possible documentation changes
• I've made sure that any changes to dev or deploy have been reflected in the internal flowchart.

[github-actions]

We detected some changes at either packages/*/src or packages/cli-kit/assets/cli-ruby/** and there are no updates in the .changeset.
If the changes are user-facing, run "pnpm changeset add" to track your changes and include them in the next release CHANGELOG.

[github-actions]

Coverage report

St.❔	Category	Percentage	Covered / Total
🟡	Statements	72.88% (-0.01% 🔻)	6153/8443
🟡	Branches	70.11% (-0.02% 🔻)	2970/4236
🟡	Functions	71.82%	1570/2186
🟡	Lines	74.01% (-0.01% 🔻)	5843/7895

Show files with reduced coverage 🔻

St.❔	File	Statements	Branches	Functions	Lines
🟢	... / ConcurrentOutput.tsx	97.62% (-2.38% 🔻)	75% (-8.33% 🔻)	100%	97.44% (-2.56% 🔻)

Test suite run success

1434 tests passing in 664 suites.

Report generated by 🧪jest coverage report action from 9e6cbd9

[Arkham]

LGTM!