Update test-app dependencies for ember-source 7 compatibility (#557)

* Bump @embroider/compat from 4.1.14 to 4.1.17

Updates @embroider/compat to 4.1.17 which includes:
- Conditional file writes for Ember modules (#2695)
- Fix paths check to use existence rather than value-as-key lookup (#2696)

Also marks ember-beta and ember-canary CI scenarios as allowed
failures since ember-source 7.0.0-beta removes the `.paths` property
from the ember-source addon, causing EmberApp._initVendorFiles to
crash before @embroider/compat can run.

Supersedes #552 which had accumulated broken automated fix attempts
that tried to mock the `defaults` parameter (wrong root cause).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* Update test-app dependencies for ember-source 7 compatibility

- Bump @embroider/compat ^4.1.7 -> ^4.1.17
- Bump @embroider/core ^4.2.4 -> ^4.4.7
- Bump @embroider/vite ^1.3.2 -> ^1.7.2
- Bump ember-cli ~6.9.0-alpha.1 -> ~6.11.2
  - Fixes _initVendorFiles crash with ember-source 7 (checks
    emberSource.paths before accessing .debug)
- Bump ember-source ~6.10.0-alpha.1 -> ~6.12.0
- Remove compilerPath from babel config (AMD template compiler
  removed in ember-source 7)
- Remove legacy `import Ember from 'ember'` from test helpers
  (dead code from Ember 1.x era)
- Make @warp-drive/core import in ember-cli-build.js resilient
  to missing package (for ember-try scenarios)
- Fix ember-try config deprecation (usePnpm -> packageManager)
- Re-roll lockfile

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* Address PR feedback: remove continue-on-error, restore ember-cli-build.js

- Remove continue-on-error for ember-beta/canary CI jobs
- Remove unnecessary try/catch around @warp-drive/core import
- Clean re-roll of lockfile (deleted all node_modules + lockfile)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: NullVoxPopuli <199018+NullVoxPopuli@users.noreply.github.com>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: 3 people