fix(create-app): pin jest and @jest/environment-jsdom-abstract to ~30.2.0

30.4.0 introduced synchronous require(ESM) that requires Node v24.9+,
breaking tests on Node 22. 30.3.0 pulls in @sinonjs/fake-timers@^15
which conflicts with @types/sinon@^17 (used by aws-sdk-client-mock).
30.2.0 avoids both issues cleanly.

Resets lockfile to a clean base-install from master constraints.

Signed-off-by: Fredrik Adelöw <freben@gmail.com>
Co-authored-by: Cursor <cursoragent@cursor.com>

package.json

@@ -133,7 +133,7 @@
     "@backstage/eslint-plugin": "workspace:*",
     "@backstage/repo-tools": "workspace:*",
     "@changesets/cli": "^2.14.0",
-    "@jest/environment-jsdom-abstract": "~30.3.0",
+    "@jest/environment-jsdom-abstract": "~30.2.0",
     "@octokit/rest": "^19.0.3",
     "@playwright/test": "^1.32.3",
     "@spotify/eslint-plugin": "^15.0.0",
@@ -162,7 +162,7 @@
     "eslint-plugin-testing-library": "^7.0.0",
     "fs-extra": "^11.2.0",
     "husky": "^9.0.0",
-    "jest": "~30.3.0",
+    "jest": "~30.2.0",
     "js-yaml": "^4.1.1",
     "jsdom": "^27",
     "lint-staged": "^16.0.0",