Move @testing-library/react to devDeps (#9309)

Author: t3chguy

package.json

@@ -60,7 +60,6 @@
     "@matrix-org/react-sdk-module-api": "^0.0.3",
     "@sentry/browser": "^6.11.0",
     "@sentry/tracing": "^6.11.0",
-    "@testing-library/react": "^12.1.5",
     "@types/geojson": "^7946.0.8",
     "await-lock": "^2.1.0",
     "blurhash": "^1.1.3",
@@ -139,6 +138,7 @@
     "@percy/cypress": "^3.1.1",
     "@sentry/types": "^6.10.0",
     "@sinonjs/fake-timers": "^9.1.2",
+    "@testing-library/react": "^12.1.5",
     "@types/classnames": "^2.2.11",
     "@types/commonmark": "^0.27.4",
     "@types/counterpart": "^0.18.1",