openjfx{17,21,23}: fix build with GCC 14 (#365724)

.github/labeler.yml

···
         - pkgs/development/compilers/corretto/**/*
         - pkgs/development/compilers/graalvm/**/*
         - pkgs/development/compilers/openjdk/**/*
+        - pkgs/by-name/op/openjfx/**/*
         - pkgs/development/compilers/semeru-bin/**/*
         - pkgs/development/compilers/temurin-bin/**/*
         - pkgs/development/compilers/zulu/**/*

pkgs/by-name/op/openjfx/package.nix

···
 
   __darwinAllowLocalNetworking = true;
 
+  # GCC 14 makes these errors by default
+  env.NIX_CFLAGS_COMPILE = "-Wno-error=incompatible-pointer-types -Wno-error=int-conversion";
   env.config = writeText "gradle.properties" ''
     CONF = Release
     JDK_HOME = ${jdk-bootstrap.home}