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>

.github/CODEOWNERS

@@ -382,7 +382,7 @@
 /.nxignore @grafana/frontend-ops
 /tsconfig.json @grafana/frontend-ops
 /.editorconfig @grafana/frontend-ops
-/.eslintignore @grafana/frontend-ops
+/eslint.config.js @grafana/frontend-ops
 /.gitattributes @grafana/frontend-ops
 /.gitignore @grafana/frontend-ops
 /.nvmrc @grafana/frontend-ops
@@ -392,7 +392,6 @@
 /yarn.lock @grafana/frontend-ops
 /lerna.json @grafana/frontend-ops
 /.prettierrc.js @grafana/frontend-ops
-/.eslintrc @grafana/frontend-ops
 /.vim @zoltanbedi
 /jest.config.js @grafana/frontend-ops
 /latest.json @grafana/frontend-ops