fix(deps): update dependency rxjs to ^6.6.4

Author: renovate-bot

package.json

@@ -65,7 +65,7 @@
   "dependencies": {
     "@sourcegraph/extension-api-classes": "^1.1.0",
     "@types/sinon": "9.0.4",
-    "rxjs": "^6.5.1",
+    "rxjs": "^6.6.4",
     "sinon": "^9.0.2",
     "sourcegraph": "^24.8.0"
   }

yarn.lock

@@ -5933,10 +5933,10 @@ rxjs-report-usage@^1.0.4:
     glob "~7.1.6"
     prompts "~2.3.2"
 
-rxjs@^6.5.1:
-  version "6.5.5"
-  resolved "https://registry.npmjs.org/rxjs/-/rxjs-6.5.5.tgz#c5c884e3094c8cfee31bf27eb87e54ccfc87f9ec"
-  integrity sha512-WfQI+1gohdf0Dai/Bbmk5L5ItH5tYqm3ki2c5GdWhKjalzjg93N3avFjVStyZZz+A2Em+ZxKH5bNghw9UeylGQ==
+rxjs@^6.6.4:
+  version "6.6.6"
+  resolved "https://registry.yarnpkg.com/rxjs/-/rxjs-6.6.6.tgz#14d8417aa5a07c5e633995b525e1e3c0dec03b70"
+  integrity sha512-/oTwee4N4iWzAMAL9xdGKjkEHmIwupR3oXbQjCKywF1BeFohswF3vZdogbmEF6pZkOsXTzWkrZszrWpQTByYVg==
   dependencies:
     tslib "^1.9.0"