Frontend: Update to Eslint 9 (#94823)

* chore(eslint): bump all eslint related packages to latest

* chore(eslint): update linting scripts work with v9

* chore(eslint): introduce flat config

* chore(eslint): delete legacy configs

* feat(grafana-eslint-rules): update rules to use eslint 9 APIs

* chore(eslint): migrate all nested eslintrc files over to root config

* chore(packages): bump eslint dependencies

* feat(betterer): make it work with eslint 9

* style(grafana-data): remove non-existant ban-types rule from disable declarations

* chore(wip): [wip] link eslint-config-grafana

* chore(packages): add @eslint/compat

* chore(eslint): add compat to testing library and fix alerting rules

* chore(eslint): bump grafana eslint-config to v8

* chore(explore): delete legacy eslint config

* chore: clean codeowners file, remove grafana/eslint-config from e2e plugins

* test(eslint-rules): fix no-border-radius-literal and no-aria-label-e2e-selectors rule tests

* Add .js to prettier checks so new eslint.config.js file isn't missed

* chore(eslint): move emotion/syntax-preference to grafana/defaults

* test(eslint): use core-js structured-clone

* revert(services): undo merge backend-format githook changes

* test(eslint-rules): remove structured-clone polyfill from tests

* chore(eslint): add back public/lib/monaco to ignore list, sort alphabetically

* chore(e2e-plugins): remove eslint config 7 from plugins package.json

---------

Co-authored-by: Tom Ratcliffe <tom.ratcliffe@grafana.com>

e2e/test-plugins/grafana-extensionstest-app/package.json

@@ -11,7 +11,6 @@
   "author": "Grafana Labs",
   "license": "Apache-2.0",
   "devDependencies": {
-    "@grafana/eslint-config": "7.0.0",
     "@grafana/plugin-configs": "11.4.0-pre",
     "@types/lodash": "4.17.7",
     "@types/node": "20.14.14",

e2e/test-plugins/grafana-test-datasource/package.json

@@ -11,7 +11,6 @@
   "author": "Grafana",
   "license": "Apache-2.0",
   "devDependencies": {
-    "@grafana/eslint-config": "7.0.0",
     "@grafana/plugin-configs": "11.4.0-pre",
     "@types/lodash": "4.17.7",
     "@types/node": "20.14.14",