[chore] Update setting testrig loglevel (#2870)

cmp.Or was introduced in Go 1.22 and picks the first value that's not
the zero value for the type. For a string, the zero value is the empty
string, which is what os.Getenv will return if the environment variable
is not set. That then results in "error" being returned instead.

This allows loading an environment variable with a default without
having to do the check and write out the conditional.

testrig/config.go

@@ -18,6 +18,7 @@
 package testrig
 
 import (
+	"cmp"
 	"os"
 	"time"
 
@@ -34,16 +35,8 @@ func InitTestConfig() {
 	})
 }
 
-func logLevel() string {
-	level := "error"
-	if lv := os.Getenv("GTS_LOG_LEVEL"); lv != "" {
-		level = lv
-	}
-	return level
-}
-
 var testDefaults = config.Configuration{
-	LogLevel:           logLevel(),
+	LogLevel:           cmp.Or(os.Getenv("GTS_LOG_LEVEL"), "error"),
 	LogTimestampFormat: "02/01/2006 15:04:05.000",
 	LogDbQueries:       true,
 	ApplicationName:    "gotosocial",