(core) Two fixes to tests affected by changes that came from grist-core.

Summary:
- For python2, skip some tests of renaming which produce different results
  because of an un-upgradable astroid version.
- Fix test affected by pyCall() having changed to async; avoid hanging timeout
  callback in case of error.

Test Plan: All test cases should now pass (with 4 getting skipped)

Reviewers: paulfitz

Reviewed By: paulfitz

Differential Revision: https://phab.getgrist.com/D3819

app/server/lib/NSandbox.ts

@@ -229,9 +229,11 @@ export class NSandbox implements ISandbox {
       // (or just benign if the doc is big).
       log.rawWarn('Slow pyCall', {...this._logMeta, funcName});
     }, 10000);
-    const result = await this._pyCallWait(funcName, startTime);
-    clearTimeout(slowCallCheck);
-    return result;
+    try {
+      return await this._pyCallWait(funcName, startTime);
+    } finally {
+      clearTimeout(slowCallCheck);
+    }
   }
 
   /**