[MM-62408] Server Code Coverage with Fully Parallel Tests (#30078)

* TestPool

* Store infra

* Store tests updates

* Bump maximum concurrent postgres connections

* More infra

* channels/jobs

* channels/app

* channels/api4

* Protect i18n from concurrent access

* Replace some use of os.Setenv

* Remove debug

* Lint fixes

* Fix more linting

* Fix test

* Remove use of Setenv in drafts tests

* Fix flaky TestWebHubCloseConnOnDBFail

* Fix merge

* [MM-62408] Add CI job to generate test coverage (#30284)

* Add CI job to generate test coverage

* Remove use of Setenv in drafts tests

* Fix flaky TestWebHubCloseConnOnDBFail

* Fix more Setenv usage

* Fix more potential flakyness

* Remove parallelism from flaky test

* Remove conflicting env var

* Fix

* Disable parallelism

* Test atomic covermode

* Disable parallelism

* Enable parallelism

* Add upload coverage step

* Fix codecov.yml

* Add codecov.yml

* Remove redundant workspace field

* Add Parallel() util methods and refactor

* Fix formatting

* More formatting fixes

* Fix reporting

server/channels/app/notify_admin_test.go

@@ -15,6 +15,7 @@ import (
 )
 
 func Test_SendNotifyAdminPosts(t *testing.T) {
+	mainHelper.Parallel(t)
 	t.Run("no error sending non trial upgrade post when no notifications are available", func(t *testing.T) {
 		th := Setup(t).InitBasic()
 		defer th.TearDown()
@@ -65,7 +66,7 @@ func Test_SendNotifyAdminPosts(t *testing.T) {
 		// message sending is async, wait time for it
 		var channel *model.Channel
 		var err error
-		var timeout = 5 * time.Second
+		timeout := 5 * time.Second
 		begin := time.Now()
 		for {
 			if time.Since(begin) > timeout {
@@ -112,7 +113,7 @@ func Test_SendNotifyAdminPosts(t *testing.T) {
 		// message sending is async, wait time for it
 		var channel *model.Channel
 		var err error
-		var timeout = 5 * time.Second
+		timeout := 5 * time.Second
 		begin := time.Now()
 		for {
 			if time.Since(begin) > timeout {
@@ -233,7 +234,7 @@ func Test_SendNotifyAdminPosts(t *testing.T) {
 		// message sending is async, wait time for it
 		var channel *model.Channel
 		var err error
-		var timeout = 5 * time.Second
+		timeout := 5 * time.Second
 		begin := time.Now()
 		for {
 			if time.Since(begin) > timeout {