chore(app-defaults): migrate to Jest 30 (#3006)

Install Jest 30 peer dependencies as required by @backstage/cli 0.36.0.
Remove the custom jest-environment-jsdom-suppress-css package, as JSDOM 27
natively handles CSS @layer declarations that previously caused parse errors.

Signed-off-by: Jon Koops <jonkoops@gmail.com>

Author: jonkoops

workspaces/app-defaults/package.json

@@ -42,6 +42,10 @@
     "@backstage/e2e-test-utils": "^0.1.2",
     "@backstage/repo-tools": "^0.17.0",
     "@changesets/cli": "^2.27.1",
+    "@jest/environment-jsdom-abstract": "^30.3.0",
+    "@types/jest": "^30.0.0",
+    "jest": "^30.3.0",
+    "jsdom": "^27.1.0",
     "knip": "^5.27.4",
     "node-gyp": "^9.0.0",
     "prettier": "^2.3.2",

workspaces/app-defaults/packages/app/package.json

@@ -11,9 +11,6 @@
   "backstage": {
     "role": "frontend"
   },
-  "jest": {
-    "testEnvironment": "@internal/jest-environment-jsdom-suppress-css"
-  },
   "scripts": {
     "start": "backstage-cli package start",
     "build": "backstage-cli package build",
@@ -59,7 +56,6 @@
   },
   "devDependencies": {
     "@backstage/frontend-test-utils": "^0.5.1",
-    "@internal/jest-environment-jsdom-suppress-css": "workspace:^",
     "@playwright/test": "^1.58.2",
     "@testing-library/dom": "^10.0.0",
     "@testing-library/jest-dom": "^6.0.0",

workspaces/app-defaults/packages/jest-environment-jsdom-suppress-css/jest-environment-jsdom-suppress-css.cjs

@@ -35,9 +35,6 @@
       "@red-hat-developer-hub/backstage-plugin-app-auth"
     ]
   },
-  "jest": {
-    "testEnvironment": "@internal/jest-environment-jsdom-suppress-css"
-  },
   "sideEffects": false,
   "configSchema": "config.d.ts",
   "scripts": {
@@ -63,7 +60,6 @@
   "devDependencies": {
     "@backstage/cli": "^0.36.0",
     "@backstage/test-utils": "^1.7.16",
-    "@internal/jest-environment-jsdom-suppress-css": "workspace:^",
     "@testing-library/jest-dom": "^6.0.0",
     "@testing-library/react": "^16.0.0",
     "@types/react": "^18",

workspaces/app-defaults/packages/jest-environment-jsdom-suppress-css/package.json

@@ -35,9 +35,6 @@
       "@red-hat-developer-hub/backstage-plugin-app-integrations"
     ]
   },
-  "jest": {
-    "testEnvironment": "@internal/jest-environment-jsdom-suppress-css"
-  },
   "sideEffects": false,
   "scripts": {
     "start": "backstage-cli package start",
@@ -59,7 +56,6 @@
   "devDependencies": {
     "@backstage/cli": "^0.36.0",
     "@backstage/test-utils": "^1.7.16",
-    "@internal/jest-environment-jsdom-suppress-css": "workspace:^",
     "@testing-library/jest-dom": "^6.0.0",
     "@testing-library/react": "^16.0.0",
     "@types/react": "^18",

workspaces/app-defaults/plugins/app-auth/package.json

@@ -35,9 +35,6 @@
       "@red-hat-developer-hub/backstage-plugin-app-react"
     ]
   },
-  "jest": {
-    "testEnvironment": "@internal/jest-environment-jsdom-suppress-css"
-  },
   "sideEffects": false,
   "scripts": {
     "start": "backstage-cli package start",
@@ -61,7 +58,6 @@
   "devDependencies": {
     "@backstage/cli": "^0.36.0",
     "@backstage/test-utils": "^1.7.16",
-    "@internal/jest-environment-jsdom-suppress-css": "workspace:^",
     "@testing-library/jest-dom": "^6.0.0",
     "@testing-library/react": "^16.0.0",
     "cross-fetch": "^4.0.0",