chore(deps-dev): bump rxjs from 6.5.2 to 6.6.6

Bumps [rxjs](https://github.com/reactivex/rxjs) from 6.5.2 to 6.6.6.
- [Release notes](https://github.com/reactivex/rxjs/releases)
- [Changelog](https://github.com/ReactiveX/rxjs/blob/6.6.6/CHANGELOG.md)
- [Commits](ReactiveX/rxjs@6.5.2...6.6.6)

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

Author: dependabot-preview[bot]

yarn.lock

@@ -7287,9 +7287,9 @@ run-parallel@^1.1.9:
   integrity sha512-DEqnSRTDw/Tc3FXf49zedI638Z9onwUotBMiUFKmrO2sdFKIbXamXGQ3Axd4qgphxKB4kw/qP1w5kTxnfU1B9Q==
 
 rxjs@^6.3.3, rxjs@^6.4.0, rxjs@^6.5.2:
-  version "6.5.2"
-  resolved "https://registry.yarnpkg.com/rxjs/-/rxjs-6.5.2.tgz#2e35ce815cd46d84d02a209fb4e5921e051dbec7"
-  integrity sha512-HUb7j3kvb7p7eCUHE3FqjoDsC1xfZQ4AHFWfTKSpZ+sAhhz5X1WX0ZuUqWbzB2QhSLp3DoLUG+hMdEDKqWo2Zg==
+  version "6.6.6"
+  resolved "https://registry.yarnpkg.com/rxjs/-/rxjs-6.6.6.tgz#14d8417aa5a07c5e633995b525e1e3c0dec03b70"
+  integrity sha512-/oTwee4N4iWzAMAL9xdGKjkEHmIwupR3oXbQjCKywF1BeFohswF3vZdogbmEF6pZkOsXTzWkrZszrWpQTByYVg==
   dependencies:
     tslib "^1.9.0"