fix GOOS parsing to match expected GHA RUNNER_OS values (#2422)

github actions reports RUNNER_OS for linux and windows with capital letters (Linux, Windows). This should increase compatibility when runner uses `-self-hosted`

Co-authored-by: Jason Song <i@wolfogre.com>

pkg/container/host_environment.go

@@ -435,6 +435,8 @@ func goArchToActionArch(arch string) string {
 
 func goOsToActionOs(os string) string {
 	osMapper := map[string]string{
+		"linux": "Linux",
+		"windows": "Windows",
 		"darwin": "macOS",
 	}
 	if os, ok := osMapper[os]; ok {