Update contrib/libs/flac to 1.5.0

commit_hash:c4501f10c86d8db0ad06708efd862535f5820b59

Author: robot-piglet

build/conf/licenses.json

@@ -45,6 +45,7 @@
             "GCC-exception-3.1",
             "GDAL",
             "GFDL-1.1-or-later",
+            "GFDL-1.3-only",
             "GFDL-1.3-or-later",
             "Go-License",
             "Google-Patent-License-Webm",