[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/ratelimit_test.go

@@ -27,6 +27,7 @@ func genRateLimitSettings(useAuth, useIP bool, header string) *model.RateLimitSe
 }
 
 func TestNewRateLimiterSuccess(t *testing.T) {
+	mainHelper.Parallel(t)
 	settings := genRateLimitSettings(false, false, "")
 	rateLimiter, err := NewRateLimiter(settings, nil)
 	require.NotNil(t, rateLimiter)
@@ -38,6 +39,7 @@ func TestNewRateLimiterSuccess(t *testing.T) {
 }
 
 func TestNewRateLimiterFailure(t *testing.T) {
+	mainHelper.Parallel(t)
 	invalidSettings := genRateLimitSettings(false, false, "")
 	invalidSettings.MaxBurst = model.NewPointer(-100)
 	rateLimiter, err := NewRateLimiter(invalidSettings, nil)
@@ -50,6 +52,7 @@ func TestNewRateLimiterFailure(t *testing.T) {
 }
 
 func TestGenerateKey(t *testing.T) {
+	mainHelper.Parallel(t)
 	cases := []struct {
 		useAuth         bool
 		useIP           bool
@@ -91,6 +94,7 @@ func TestGenerateKey(t *testing.T) {
 }
 
 func TestGenerateKey_TrustedHeader(t *testing.T) {
+	mainHelper.Parallel(t)
 	req := httptest.NewRequest("GET", "/", nil)
 	req.RemoteAddr = "10.10.10.5:80"
 	req.Header.Set("X-Forwarded-For", "10.6.3.1, 10.5.1.2")