Deploy main eacf1e7 to prod

Replaces #559, which conflicted.

Model: opus-5-5

internal/config/sentry_test.go

@@ -1,12 +1,12 @@
 package config_test
 
 import (
-	"os"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	"sneak.berlin/go/webhooker/internal/config"
+	"sneak.berlin/go/webhooker/internal/config/configtest"
 )
 
 // envKeySentryDSN is the variable envSentryDSN reads in production.
@@ -101,10 +101,10 @@ func TestEnvSentryDSN(t *testing.T) {
 		t.Run(tt.name, func(t *testing.T) {
 			// Cannot use t.Parallel() here because t.Setenv
 			// is incompatible with parallel subtests.
+			configtest.ClearEnv(t)
+
 			if tt.set {
 				t.Setenv(envKeySentryDSN, tt.value)
-			} else {
-				require.NoError(t, os.Unsetenv(envKeySentryDSN))
 			}
 
 			got, err := config.EnvSentryDSNForTest(envKeySentryDSN)