Upgrade to Babel 8, Vite 8, and babel-plugin-ember-template-compilation 4

Bump @babel/core, @babel/eslint-parser, @babel/plugin-transform-runtime,
and @babel/runtime to ^8.x. Remove useESModules and regenerator options
from @babel/plugin-transform-runtime config (both removed in Babel 8).
Switch @babel/eslint-parser import from the removed /experimental-worker
entry point to the main entry point.

Bump vite to ^8.0.0 (now using Rolldown/Oxc instead of esbuild/Rollup).
Bump @rollup/plugin-babel to ^7.1.0 and
babel-plugin-ember-template-compilation to ^4.0.0.

Patch ember-concurrency@5.2.0 to remove the api.assertVersion(7) call
that is incompatible with Babel 8 (ember-concurrency has not yet
released a Babel 8-compatible version).

package.json

@@ -39,10 +39,10 @@
     "version": "pnpm build && git add release/"
   },
   "devDependencies": {
-    "@babel/core": "^7.28.5",
-    "@babel/eslint-parser": "^7.28.5",
-    "@babel/plugin-transform-runtime": "^7.28.5",
-    "@babel/runtime": "^7.28.4",
+    "@babel/core": "^8.0.1",
+    "@babel/eslint-parser": "^8.0.1",
+    "@babel/plugin-transform-runtime": "^8.0.1",
+    "@babel/runtime": "^8.0.0",
     "@ember/test-helpers": "^5.4.3",
     "@ember/test-waiters": "^4.1.2",
     "@embroider/core": "^4.6.3",
@@ -53,13 +53,13 @@
     "@eslint/js": "^9.39.2",
     "@glimmer/component": "^2.1.1",
     "@remotestorage/module-places": "~1.3.0",
-    "@rollup/plugin-babel": "^6.1.0",
+    "@rollup/plugin-babel": "^7.1.0",
     "@warp-drive/core": "~5.8.2",
     "@warp-drive/ember": "~5.8.2",
     "@warp-drive/json-api": "~5.8.2",
     "@warp-drive/legacy": "~5.8.2",
     "@warp-drive/utilities": "~5.8.2",
-    "babel-plugin-ember-template-compilation": "^3.0.1",
+    "babel-plugin-ember-template-compilation": "^4.0.0",
     "concurrently": "^9.2.1",
     "decorator-transforms": "^2.4.0",
     "ember-cli": "^6.12.0",
@@ -93,7 +93,7 @@
     "stylelint": "^16.26.1",
     "stylelint-config-standard": "^38.0.0",
     "testem": "^3.20.1",
-    "vite": "^7.3.0"
+    "vite": "^8.0.0"
   },
   "engines": {
     "node": ">= 22"