convert windows file path to file uri in TestVerifiedHash

this fixes the following unit test failure on windows:
```
=== RUN   TestVerifiedHash
    metadata_test.go:214:
        	Error Trace:	D:/a/crc/crc/pkg/crc/machine/bundle/metadata_test.go:214
        	            				D:/a/crc/crc/pkg/crc/machine/bundle/metadata_test.go:193
        	Error:      	Received unexpected error:
        	            	parse "file://D:\\a\\crc\\crc\\pkg\\crc\\machine\\bundle\\testdata\\sha256sum_correct_4.13.0.txt.sig": invalid port ":\\a\\crc\\crc\\pkg\\crc\\machine\\bundle\\testdata\\sha256sum_correct_4.13.0.txt.sig" after host
        	Test:       	TestVerifiedHash
```

the correct file URI should be 'file://D/a/crc/crc/pkg/crc/machine/bundle..'

pkg/crc/machine/bundle/metadata_test.go

@@ -209,5 +209,9 @@ func TestVerifiedHash(t *testing.T) {
 func testDataURI(t *testing.T, sha256sum string) string {
 	absPath, err := filepath.Abs(filepath.Join("testdata", sha256sum))
 	require.NoError(t, err)
-	return fmt.Sprintf("file:///%s", absPath)
+	// when its a windows path with drive letter
+	if volume := filepath.VolumeName(absPath); volume != "" {
+		return fmt.Sprintf("file://%s/%s", volume[:1], absPath[3:])
+	}
+	return fmt.Sprintf("file:///%s", filepath.ToSlash(absPath))
 }