Align stdeb dependencies with setup.py (#101)

Follow-up to 4b2f3a8

Author: cottsay

stdeb.cfg

@@ -1,7 +1,7 @@
 [DEFAULT]
-Depends3: python3-setuptools, python3-importlib-metadata
+Depends3: python3 (>= 3.8) | python3-importlib-metadata
 Conflicts3: python-osrf-pycommon
 Suite3: focal jammy noble bookworm trixie
-X-Python3-Version: >= 3.8
+X-Python3-Version: >= 3.5
 No-Python2:
 Upstream-Version-Suffix: +upstream