Use latestRelease func to determine latest upstream release in getExp…

…ectedTargetLatest

upgrade/steps_helpers.go

@@ -511,20 +511,12 @@ var getExpectedTarget = stepv2.Func21("Get Expected Target", func(ctx context.Co
 // release.
 var getExpectedTargetLatest = stepv2.Func21E("From Upstream Releases", func(ctx context.Context,
 	name, upstreamOrg string) (*UpstreamUpgradeTarget, error) {
-	latest := stepv2.Cmd(ctx, "gh", "release", "list",
-		"--repo="+upstreamOrg+"/"+GetContext(ctx).UpstreamProviderName,
-		"--limit=1",
-		"--exclude-drafts",
-		"--exclude-pre-releases")
-
-	tok := strings.Fields(latest)
-	contract.Assertf(len(tok) > 0, fmt.Sprintf("no releases found in %s/%s",
-		upstreamOrg, GetContext(ctx).UpstreamProviderName))
-	v, err := semver.NewVersion(tok[0])
+	upstreamRepo := upstreamOrg + "/" + GetContext(ctx).UpstreamProviderName
+	latest, err := latestRelease(ctx, upstreamRepo)
 	if err != nil {
 		return nil, err
 	}
-	return &UpstreamUpgradeTarget{Version: v}, nil
+	return &UpstreamUpgradeTarget{Version: latest}, nil
 })
 
 // Figure out what version of upstream to target by looking at specific pulumi-bot