chore: Simplify license routines (#64068)

There's no need to track they haven't been called twice, this is a
programming error and should not happen. We don't need to maintain a
global int for that, IMO which just makes it harder to call in tests
etc.

Test plan: Local stack still works, code review.

cmd/frontend/internal/dotcom/productsubscription/license_anomaly.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"fmt"
 	"net/url"
-	"sync/atomic"
 	"time"
 
 	"github.com/derision-test/glock"
@@ -23,16 +22,10 @@ import (
 
 const licenseAnomalyCheckKey = "license_anomaly_check"
 
-var licenseAnomalyCheckers uint32
-
 // StartCheckForAnomalousLicenseUsage checks for anomalous license usage.
 //
 // TODO(@bobheadxi): Migrate to Enterprise Portal https://linear.app/sourcegraph/issue/CORE-182
 func StartCheckForAnomalousLicenseUsage(logger log.Logger, db database.DB) {
-	if atomic.AddUint32(&licenseAnomalyCheckers, 1) != 1 {
-		panic("StartCheckForAnomalousLicenseUsage called more than once")
-	}
-
 	dotcom := conf.Get().Dotcom
 	if dotcom == nil {
 		return

cmd/frontend/internal/dotcom/productsubscription/license_expiration.go

@@ -3,7 +3,6 @@ package productsubscription
 import (
 	"context"
 	"fmt"
-	"sync/atomic"
 	"time"
 
 	"github.com/derision-test/glock"
@@ -19,17 +18,11 @@ import (
 
 const lastLicenseExpirationCheckKey = "last_license_expiration_check"
 
-var licenseExpirationCheckers uint32
-
 // StartCheckForUpcomingLicenseExpirations checks for upcoming license expirations once per day.
 //
 // TODO(@bobheadxi): Migrate to Enterprise Portal
 // https://linear.app/sourcegraph/issue/CORE-183
 func StartCheckForUpcomingLicenseExpirations(logger log.Logger, db database.DB) {
-	if atomic.AddUint32(&licenseExpirationCheckers, 1) != 1 {
-		panic("StartCheckForUpcomingLicenseExpirations called more than once")
-	}
-
 	dotcom := conf.Get().Dotcom
 	if dotcom == nil {
 		return