refactor: Remove linux build tag, scope OSFamilyEnvVar to private var, remove unused constant

Author: briannamagtoto

agent/config/parse_linux.go

@@ -28,7 +28,7 @@ import (
 )
 
 const (
-	OSFamilyEnvVar = "ECS_DETAILED_OS_FAMILY"
+	osFamilyEnvVar = "ECS_DETAILED_OS_FAMILY"
 )
 
 func parseGMSACapability() BooleanDefaultFalse {
@@ -119,7 +119,7 @@ func GetOSFamily() string {
 // GetDetailedOSFamily returns the operating system family for linux based ecs instances.
 // it first checks the ECS_DETAILED_OS_FAMILY environment variable set by ecs-init, and falls back to "LINUX" if not set
 func GetDetailedOSFamily() string {
-	detailedOSFamily, ok := os.LookupEnv(OSFamilyEnvVar)
+	detailedOSFamily, ok := os.LookupEnv(osFamilyEnvVar)
 	if !ok {
 		return strings.ToUpper(OSType)
 	}

agent/config/parse_linux_test.go

@@ -111,14 +111,14 @@ func TestParseTaskPidsLimit_Unset(t *testing.T) {
 }
 
 func TestGetDetailedOSFamilyWithValidValue(t *testing.T) {
-	t.Setenv(OSFamilyEnvVar, "debian_11")
+	t.Setenv(osFamilyEnvVar, "debian_11")
 
 	result := GetDetailedOSFamily()
 	assert.Equal(t, "debian_11", result)
 }
 
 func TestGetDetailedOSFamilyWithEmptyValue(t *testing.T) {
-	t.Setenv(OSFamilyEnvVar, "")
+	t.Setenv(osFamilyEnvVar, "")
 
 	result := GetDetailedOSFamily()
 	assert.Equal(t, "", result)
@@ -135,7 +135,7 @@ func TestGetOSFamilyAlwaysReturnsLinux(t *testing.T) {
 	osFamily := GetOSFamily()
 	assert.Equal(t, "LINUX", osFamily)
 
-	t.Setenv(OSFamilyEnvVar, "debian_11")
+	t.Setenv(osFamilyEnvVar, "debian_11")
 	osFamily = GetOSFamily()
 	assert.Equal(t, "LINUX", osFamily)
 }