Add post-deploy message for extensions migration to Dev Dash

[isaacroldan]

WHY are these changes introduced?

To improve the developer experience when migrating extensions to the Developer Dashboard by providing clear next steps after deployment.

WHAT is this pull request doing?

This PR enhances the deploy process to detect when extensions are being migrated to the Developer Dashboard and provides guidance to developers on next steps. Specifically:

1. Displays a "Next steps" section in the success message when extensions are migrated

How to test your changes?

1. Deploy an app with extensions that haven't been migrated to the Developer Dashboard
   1b. You can force this locally by removing the user_identifier from some extensions in your DB
2. Verify that the success message includes the "Next steps" section with instructions
3. Deploy an app with extensions that have already been migrated
4. Verify that the standard success message appears without the migration guidance

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

Checklist

• I've considered possible cross-platform impacts (Mac, Linux, Windows)
• I've considered possible documentation changes

[isaacroldan]

• Add post-deploy message for extensions migration to Dev Dash #6104 👈 (View in Graphite)
• main

This stack of pull requests is managed by Graphite. Learn more about stacking.

[github-actions]

Coverage report

St.❔	Category	Percentage	Covered / Total
🟡	Statements	78.26% (+0.07% 🔼)	13050/16676
🟡	Branches	72.44% (+0.1% 🔼)	6354/8771
🟡	Functions	78.18% (+0.02% 🔼)	3376/4318
🟡	Lines	78.67% (+0.08% 🔼)	12358/15708

Show files with reduced coverage 🔻

St.❔	File	Statements	Branches	Functions	Lines
🟢	... / loader.ts	93.36% (-0.09% 🔻)	85.78% (-0.27% 🔻)	97.22% (-0.08% 🔻)	94.37% (-0.06% 🔻)
🟡	... / context.ts	75.47% (+0.22% 🔼)	61.82% (+2.99% 🔼)	73.91% (-3.36% 🔻)	77.89% (+0.97% 🔼)
🟢	... / patch-app-configuration-file.ts	100% (+6.67% 🔼)	80% (-20% 🔻)	100% (+14.29% 🔼)	100% (+6.67% 🔼)

Test suite run success

3038 tests passing in 1318 suites.

Report generated by 🧪jest coverage report action from 4030098

[github-actions]

We detected some changes at packages/*/src 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.

Caution

DO NOT create changesets for features which you do not wish to be included in the public changelog of the next CLI release.