Drop incidental version f-string NameError change; keep only api_version attribute fix

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

Copilot-Session: 9e983f91-eed5-4191-b531-0eca9e696313

Author: l0lawrence

.chronus/changes/fix-api-version-validation-attr-2026-7-24-11-30-0.md

@@ -4,4 +4,4 @@ packages:
   - "@typespec/http-client-python"
 ---
 
-Fix the generated `_validation.py` `@api_version_validation` decorator so it reads the correct client config attribute for the API version. Previously it hardcoded `client._config.api_version`, but the config attribute name comes from the API-version parameter's `client_name`. For specs that name the versioning parameter something other than `apiVersion` (e.g. Azure Storage's `@apiVersion @header("x-ms-version") version: string`, which produces `self.version`), the hardcoded lookup raised `AttributeError` that the decorator silently swallowed, disabling all API-version validation for those clients. The emitter now threads the real attribute name into the decorator via a `client_api_version_name` kwarg (emitted only when it differs from the default `api_version`). Also fixes a latent `NameError` in the decorator's `unsupported` error-message branch that referenced an out-of-scope `version` variable.
+Fix the generated `_validation.py` `@api_version_validation` decorator so it reads the correct client config attribute for the API version. Previously it hardcoded `client._config.api_version`, but the config attribute name comes from the API-version parameter's `client_name`. For specs that name the versioning parameter something other than `apiVersion` (e.g. Azure Storage's `@apiVersion @header("x-ms-version") version: string`, which produces `self.version`), the hardcoded lookup raised `AttributeError` that the decorator silently swallowed, disabling all API-version validation for those clients. The emitter now threads the real attribute name into the decorator via a `client_api_version_name` kwarg (emitted only when it differs from the default `api_version`).

packages/http-client-python/generator/pygen/codegen/templates/validation.py.jinja2

@@ -49,8 +49,8 @@ def api_version_validation(**kwargs):
             if unsupported:
                 raise ValueError("".join([
                     f"'{param}' is not available in API version {client_api_version}. "
-                    f"Use service API version {param_api_version} or newer.\n"
-                    for param, param_api_version in unsupported.items()
+                    f"Use service API version {version} or newer.\n"
+                    for param, version in unsupported.items()
                 ]))
             return func(*args, **kwargs)
         return wrapper