bypass pyproject setting like license (#11025)

bypassing the pyproject setting will prevent from undefined getting set
on the pyproject toml entries

Author: l0lawrence

.chronus/changes/mismatch-2026-5-19-9-54-46.md

@@ -0,0 +1,7 @@
+---
+changeKind: internal
+packages:
+  - "@typespec/http-client-python"
+---
+
+Preserve transformed `keep-pyproject-fields` emitter options when building Python generator command arguments.

packages/http-client-python/emitter/src/emitter.ts

@@ -220,7 +220,7 @@ async function onEmitMain(context: EmitContext<PythonEmitterOptions>) {
   }
 
   for (const [key, value] of Object.entries(resolvedOptions)) {
-    if (key === "license") continue; // skip license since it is passed in codeModel
+    if (key === "license" || key === "keep-pyproject-fields") continue; // skip license + keep-pyproject-fields since it is passed in codeModel
     commandArgs[key] = value;
   }
   if (resolvedOptions["generate-packaging-files"]) {