chore(profiling): gunicorn test improvements (#11471)

- use `--worker-tmp-dir /dev/shm` as in
https://pythonspeed.com/articles/gunicorn-in-docker/,
https://docs.gunicorn.org/en/stable/faq.html#how-do-i-avoid-gunicorn-excessively-blocking-in-os-fchmod
- clean up server when the request fails

## Checklist
- [x] PR author has checked that all the criteria below are met
- The PR description includes an overview of the change
- The PR description articulates the motivation for the change
- The change includes tests OR the PR description describes a testing
strategy
- The PR description notes risks associated with the change, if any
- Newly-added code is easy to change
- The change follows the [library release note
guidelines](https://ddtrace.readthedocs.io/en/stable/releasenotes.html)
- The change includes or references documentation updates if necessary
- Backport labels are set (if
[applicable](https://ddtrace.readthedocs.io/en/latest/contributing.html#backporting))

## Reviewer Checklist
- [x] Reviewer has checked that all the criteria below are met 
- Title is accurate
- All changes are related to the pull request's stated goal
- Avoids breaking
[API](https://ddtrace.readthedocs.io/en/stable/versioning.html#interfaces)
changes
- Testing strategy adequately addresses listed risks
- Newly-added code is easy to change
- Release note makes sense to a user of the library
- If necessary, author has acknowledged and discussed the performance
implications of this PR as reported in the benchmarks PR comment
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[release branch maintenance
policy](https://ddtrace.readthedocs.io/en/latest/contributing.html#backporting)

tests/profiling_v2/test_gunicorn.py

@@ -30,7 +30,16 @@ def debug_print(*args):
 
 def _run_gunicorn(*args):
     cmd = (
-        ["ddtrace-run", "gunicorn", "--bind", "127.0.0.1:7644", "--chdir", os.path.dirname(__file__)]
+        [
+            "ddtrace-run",
+            "gunicorn",
+            "--bind",
+            "127.0.0.1:7644",
+            "--worker-tmp-dir",
+            "/dev/shm",
+            "--chdir",
+            os.path.dirname(__file__),
+        ]
         + list(args)
         + ["tests.profiling.gunicorn-app:app"]
     )
@@ -75,6 +84,9 @@ def _test_gunicorn(gunicorn, tmp_path, monkeypatch, *args):
             response = f.read().decode()
             debug_print(response)
     except Exception as e:
+        proc.terminate()
+        output = proc.stdout.read().decode()
+        print(output)
         pytest.fail("Failed to make request to gunicorn server %s" % e)
     finally:
         # Need to terminate the process to get the output and release the port