Chore: Set tsconfig target to ES6 (#44842)

* chore(tsconfig): update grafana/tsconfig to 1.2.0 for outputting es6

* rewrote the unsubscription part to use first().

* test: update failing tests to work with es6 output

* removed bug where we dispatch a promise instead of an array of ritch history.

Co-authored-by: Marcus Andersson <marcus.andersson@grafana.com>

package.json

@@ -87,7 +87,7 @@
     "@grafana/e2e": "workspace:*",
     "@grafana/eslint-config": "2.5.2",
     "@grafana/toolkit": "workspace:*",
-    "@grafana/tsconfig": "^1.1.0-rc1",
+    "@grafana/tsconfig": "^1.2.0-rc1",
     "@lingui/cli": "3.13.2",
     "@lingui/macro": "3.13.2",
     "@microsoft/api-extractor": "7.19.4",