Refactor clang-tidy script to use actual compiler flags and includes (#2133)

Co-authored-by: Otto winter <otto@otto-winter.com>

esphome/components/sntp/sntp_component.cpp

@@ -8,6 +8,11 @@
 #include "sntp.h"
 #endif
 
+// Yes, the server names are leaked, but that's fine.
+#ifdef CLANG_TIDY
+#define strdup(x) (const_cast<char *>(x))
+#endif
+
 namespace esphome {
 namespace sntp {