Infra: Include trailing slash in RSS URLs to avoid 301 redirect (#2474)

Makefile

@@ -32,6 +32,7 @@ venv:
 		echo "To recreate it, remove it first with \`make clean-venv'."; \
 	else \
 		$(PYTHON) -m venv $(VENVDIR); \
+		$(VENVDIR)/bin/python3 -m pip install -U pip wheel; \
 		$(VENVDIR)/bin/python3 -m pip install -r requirements.txt; \
 		echo "The venv has been created in the $(VENVDIR) directory"; \
 	fi

generate_rss.py

@@ -167,7 +167,7 @@ def main():
             joined_authors = ", ".join(f"{name} ({email_address})" for name, email_address in parsed_authors)
         else:
             joined_authors = author
-        url = f"https://peps.python.org/pep-{pep_num:0>4}"
+        url = f"https://peps.python.org/pep-{pep_num:0>4}/"
 
         item = entry.FeedEntry()
         item.title(f"PEP {pep_num}: {title}")