Only prune the trailing spaces in Python automation result (#8160)

CHANGELOG_PENDING.md

@@ -1,5 +1,7 @@
 ### Improvements
 
+- [automation/python] - Use `rstrip` rather than `strip` for the sake of indentation
+  [#8160](https://github.com/pulumi/pulumi/pull/8160)
 - [codegen/nodejs] - Add helper function forms `$fnOutput` that accept
   `Input`s, return an `Output`, and wrap the underlying `$fn` call.
   This change addreses

sdk/python/lib/pulumi/automation/_cmd.py

@@ -60,7 +60,7 @@ def _run_pulumi_cmd(args: List[str],
                 if output == "" and process.poll() is not None:
                     break
                 if output:
-                    text = output.strip()
+                    text = output.rstrip()
                     if on_output:
                         on_output(text)
                     stdout_chunks.append(text)