Switch to using diff-cover for the Coverage gate (#33673)

* Switch to using diff-cover for the Coverage gate

Enabling developers to check their PR coverage without waiting for CI

* Remove sonar-project.properties - in automatic mode Sonar will not read this file

* Add note to CONTRIBUTING.md

* Skip sonar in MQ

apps/web/package.json

@@ -34,6 +34,7 @@
         "test:playwright:open": "nx test:playwright -- --ui",
         "test:playwright:screenshots": "nx test:playwright:screenshots --",
         "coverage": "pnpm test --coverage",
+        "coverage:diff": "diff-cover --config-file ../../diff-cover.toml coverage/lcov.info",
         "analyse:webpack-bundles": "webpack-bundle-analyzer webpack-stats.json webapp"
     },
     "dependencies": {
@@ -125,7 +126,6 @@
         "@babel/preset-env": "^7.12.11",
         "@babel/preset-react": "^7.12.10",
         "@babel/preset-typescript": "^7.12.7",
-        "@casualbot/jest-sonar-reporter": "2.7.1",
         "@element-hq/element-call-embedded": "0.19.4",
         "@element-hq/element-web-playwright-common": "workspace:*",
         "@fetch-mock/jest": "^0.2.20",
@@ -236,11 +236,6 @@
         "webpack-version-file-plugin": "^0.5.0",
         "yaml": "^2.3.3"
     },
-    "@casualbot/jest-sonar-reporter": {
-        "outputDirectory": "coverage",
-        "outputName": "jest-sonar-report.xml",
-        "relativePaths": true
-    },
     "engines": {
         "node": ">=22.18"
     },