Cleans up prints from unit test runner (#433)

# Description

When I updated `run_all_tests.sh` to be runnable from any dir (#406),
some debugging prints accidentally made it into the commit 😅
These make it quite hard to read the test output. This PR removes the
debugging `print()` calls and replaces a few others with `logging` calls
for consistency.

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## Type of change

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applicable. -->

- Bug fix (non-breaking change which fixes an issue)

## Checklist

- [x] I have run the [`pre-commit` checks](https://pre-commit.com/) with
`./orbit.sh --format`
- [ ] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [ ] I have added tests that prove my fix is effective or that my
feature works
- [x] I have run all the tests with `./orbit.sh --test` and they pass
- [ ] I have updated the changelog and the corresponding version in the
extension's `config/extension.toml` file
- [x] I have added my name to the `CONTRIBUTORS.md` or my name already
exists there

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tools/run_all_tests.py

@@ -165,16 +165,13 @@ def test_all(
             completed_process = subprocess.run(
                 ["bash", orbit_shell_path, "-p", test_path], check=True, capture_output=True, timeout=timeout
             )
-            print(f"Completed Process: {completed_process}")
-            print(f"stdout: {completed_process.stdout}")
-            print(f"stderr: {completed_process.stderr}")
         except subprocess.TimeoutExpired as e:
-            print(f"Timeout occurred: {e}")
+            logging.error(f"Timeout occurred: {e}")
             result = "TIMEDOUT"
             stdout = e.stdout
             stderr = e.stderr
         except Exception as e:
-            print(f"Exception {e}!")
+            logging.error(f"Exception {e}!")
             result = "FAILED"
             stdout = e.stdout
             stderr = e.stderr