chore(deps): bump rxjs from 6.2.2 to 7.5.7

Bumps [rxjs](https://github.com/reactivex/rxjs) from 6.2.2 to 7.5.7.
- [Release notes](https://github.com/reactivex/rxjs/releases)
- [Changelog](https://github.com/ReactiveX/rxjs/blob/master/CHANGELOG.md)
- [Commits](ReactiveX/rxjs@6.2.2...7.5.7)

---
updated-dependencies:
- dependency-name: rxjs
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

package.json

@@ -109,7 +109,7 @@
     "remarkable-mentions": "^0.1.0",
     "resize-observer-polyfill": "^1.5.1",
     "response-time": "^2.3.2",
-    "rxjs": "6.2.2",
+    "rxjs": "7.5.7",
     "sanitize-html": "^2.5.2",
     "scroll-into-view-if-needed": "1.5.0",
     "sentry-testkit": "^2.1.0",