setup: Skip UI and libpg_query when building the language server

setup.py

@@ -80,6 +80,10 @@
     ])
 
 
+def _is_langserver_build() -> bool:
+    return os.environ.get("EDGEDB_BUILD_PACKAGE", "") == "language-server"
+
+
 def _compile_build_meta(build_lib, version, pg_config, runstate_dir,
                         shared_dir, version_suffix):
     from edb.common import verutils
@@ -802,6 +806,8 @@ def finalize_options(self):
         pass
 
     def run(self):
+        if _is_langserver_build():
+            return
         _compile_libpg_query()
 
 
@@ -917,6 +923,9 @@ def finalize_options(self):
         self.set_undefined_options("build_py", ("build_lib", "build_lib"))
 
     def run(self, *args, **kwargs):
+        if _is_langserver_build():
+            return
+
         from edb import buildmeta
         from edb.common import devmode