docs: ignore two build system source files in doxygen

Author: rdmark

doc/Doxyfile.in

@@ -1062,7 +1062,7 @@ EXCLUDE_SYMLINKS       = NO
 # Note that the wildcards are matched against the file with absolute path, so to
 # exclude all test directories for example use the pattern */test/*
 
-EXCLUDE_PATTERNS       = */build/*
+EXCLUDE_PATTERNS       = */build/* */dummy.c */meson_config.h
 
 # The EXCLUDE_SYMBOLS tag can be used to specify one or more symbol names
 # (namespaces, classes, functions, etc.) that should be excluded from the