[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/busy_test.go

@@ -16,6 +16,8 @@ import (
 )
 
 func TestBusySet(t *testing.T) {
+	mainHelper.Parallel(t)
+
 	cluster := &ClusterMock{Busy: &Busy{}, t: t}
 	busy := NewBusy(cluster)
 
@@ -54,6 +56,7 @@ func TestBusySet(t *testing.T) {
 }
 
 func TestBusyExpires(t *testing.T) {
+	mainHelper.Parallel(t)
 	cluster := &ClusterMock{Busy: &Busy{}, t: t}
 	busy := NewBusy(cluster)
 
@@ -90,6 +93,7 @@ func TestBusyExpires(t *testing.T) {
 }
 
 func TestBusyRace(t *testing.T) {
+	mainHelper.Parallel(t)
 	cluster := &ClusterMock{Busy: &Busy{}, t: t}
 	busy := NewBusy(cluster)
 
@@ -148,12 +152,15 @@ func (c *ClusterMock) NotifyMsg(buf []byte)                           {}
 func (c *ClusterMock) GetClusterStats(rctx request.CTX) ([]*model.ClusterStats, *model.AppError) {
 	return nil, nil
 }
+
 func (c *ClusterMock) GetLogs(rctx request.CTX, page, perPage int) ([]string, *model.AppError) {
 	return nil, nil
 }
+
 func (c *ClusterMock) QueryLogs(rctx request.CTX, page, perPage int) (map[string][]string, *model.AppError) {
 	return nil, nil
 }
+
 func (c *ClusterMock) GenerateSupportPacket(rctx request.CTX, options *model.SupportPacketOptions) (map[string][]model.FileData, error) {
 	return nil, nil
 }
@@ -165,6 +172,7 @@ func (c *ClusterMock) HealthScore() int { return 0 }
 func (c *ClusterMock) WebConnCountForUser(userID string) (int, *model.AppError) {
 	return 0, nil
 }
+
 func (c *ClusterMock) GetWSQueues(userID, connectionID string, seqNum int64) (map[string]*model.WSQueues, error) {
 	return nil, nil
 }