[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/jobs/schedulers_test.go

@@ -3,6 +3,7 @@
 package jobs
 
 import (
+	"os"
 	"sync"
 	"testing"
 	"time"
@@ -35,6 +36,10 @@ func (scheduler *MockScheduler) ScheduleJob(c request.CTX, cfg *model.Config, pe
 }
 
 func TestScheduler(t *testing.T) {
+	if os.Getenv("ENABLE_FULLY_PARALLEL_TESTS") == "true" {
+		t.Parallel()
+	}
+
 	mockStore := &storetest.Store{}
 	defer mockStore.AssertExpectations(t)
 
@@ -171,6 +176,10 @@ func TestScheduler(t *testing.T) {
 }
 
 func TestRandomDelay(t *testing.T) {
+	if os.Getenv("ENABLE_FULLY_PARALLEL_TESTS") == "true" {
+		t.Parallel()
+	}
+
 	cases := []int64{5, 10, 100}
 	for _, c := range cases {
 		out := getRandomDelay(c)