[Testing] Resolve all promises (#3829)

* all promises in test specs should be returned

Co-authored-by: Shefali Joshi <simplyrender@gmail.com>
Co-authored-by: Andrew Henry <akhenry@gmail.com>

src/plugins/plot/pluginSpec.js

@@ -34,6 +34,7 @@ describe("the plugin", function () {
     let child;
     let openmct;
     let telemetryPromise;
+    let telemetryPromiseResolve;
     let cleanupFirst;
     let mockObjectPath;
     let telemetrylimitProvider;
@@ -78,7 +79,6 @@ describe("the plugin", function () {
 
         openmct = createOpenMct();
 
-        let telemetryPromiseResolve;
         telemetryPromise = new Promise((resolve) => {
             telemetryPromiseResolve = resolve;
         });