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>

packages/grafana-e2e/package.json

@@ -49,7 +49,7 @@
     "@babel/preset-env": "7.16.11",
     "@cypress/webpack-preprocessor": "5.11.0",
     "@grafana/e2e-selectors": "8.5.0-pre",
-    "@grafana/tsconfig": "^1.0.0-rc1",
+    "@grafana/tsconfig": "^1.2.0-rc1",
     "@mochajs/json-file-reporter": "^1.2.0",
     "babel-loader": "8.2.3",
     "blink-diff": "1.0.13",