Fix UnicodeDecodeError in print_requests.py on systems with ASCII locale

Open out.requests.txt with explicit utf-8 encoding to handle
non-ASCII characters in request bodies.

Co-authored-by: Isaac

Author: shreyas-goenka

acceptance/bin/print_requests.py

@@ -168,7 +168,7 @@ def main():
     if not requests_file.exists():
         sys.exit(f"File {requests_file} not found")
 
-    with open(requests_file) as fobj:
+    with open(requests_file, encoding="utf-8") as fobj:
         data = fobj.read()
 
     if not data: