fix(ci): artifacts includes irrelevant files #4505

Problem:
The build artifacts zip includes the `aws-toolkit-vscode.code-workspace`
file.

Solution:
Adjust the include pattern.

Author: justinmk3

buildspec/packageTestVsix.yml

@@ -32,5 +32,5 @@ phases:
 
 artifacts:
     files:
-        - aws-toolkit-vscode*
+        - aws-toolkit-vscode*vsix
     discard-paths: true