Add support for self-signed CA certificates (#2268)

Co-authored-by: Bassem Dghaidi <568794+Link-@users.noreply.github.com>
Co-authored-by: Nikola Jokic <jokicnikola07@gmail.com>
Co-authored-by: Tingluo Huang <tingluohuang@github.com>

github/actions/client.go

@@ -198,6 +198,12 @@ func (c *Client) Identifier() string {
 		)
 	}
 
+	if c.rootCAs != nil {
+		// ignoring because this cert pool is intended not to come from SystemCertPool
+		// nolint:staticcheck
+		identifier += fmt.Sprintf("rootCAs:%q", c.rootCAs.Subjects())
+	}
+
 	return uuid.NewHash(sha256.New(), uuid.NameSpaceOID, []byte(identifier), 6).String()
 }