Merge bitcoin/bitcoin#25294: test: Fix wait_for_debug_log UnicodeDecodeError

fa74b63c01 test: Fix wait_for_debug_log UnicodeDecodeError (MacroFake)

Pull request description:

  Fix the intermittent `UnicodeDecodeError` when the debug log is truncated on an (multi-byte) unicode character by treating everything as bytes.

  Also, remove the `ignore_case` option and the`re.search+re.escape` wrap. All of this is unused and doesn't exist on raw byte strings.

  Fixes https://github.com/bitcoin/bitcoin/issues/24575

ACKs for top commit:
  jonatack:
    ACK fa74b63c01
  brunoerg:
    ACK fa74b63c01

Tree-SHA512: c67c9355073e784fa8d9d48b8e79ff0c98f5ae9cd4d704ad12a76d2604733946054bc74b8ab346aa2184db23d740b85c8c13eb892d76cba92e42ebfd73f2f1bf

test/functional/test_framework/test_node.py

@@ -423,7 +423,7 @@ class TestNode():
         self._raise_assertion_error('Expected messages "{}" does not partially match log:\n\n{}\n\n'.format(str(expected_msgs), print_log))
 
     @contextlib.contextmanager
-    def wait_for_debug_log(self, expected_msgs, timeout=60, ignore_case=False):
+    def wait_for_debug_log(self, expected_msgs, timeout=60):
         """
         Block until we see a particular debug log message fragment or until we exceed the timeout.
         Return:
@@ -431,18 +431,17 @@ class TestNode():
         """
         time_end = time.time() + timeout * self.timeout_factor
         prev_size = self.debug_log_bytes()
-        re_flags = re.MULTILINE | (re.IGNORECASE if ignore_case else 0)
 
         yield
 
         while True:
             found = True
-            with open(self.debug_log_path, encoding='utf-8') as dl:
+            with open(self.debug_log_path, "rb") as dl:
                 dl.seek(prev_size)
                 log = dl.read()
 
             for expected_msg in expected_msgs:
-                if re.search(re.escape(expected_msg), log, flags=re_flags) is None:
+                if expected_msg not in log:
                     found = False
 
             if found: