Bump mypy to 1.15.0

dulwich/config.py

@@ -553,6 +553,7 @@ class ConfigFile(ConfigDict):
                     ret._values[section][setting] = value
                     setting = None
             else:  # continuation line
+                assert continuation is not None
                 if line.endswith(b"\\\n"):
                     continuation += line[:-2]
                 elif line.endswith(b"\\\r\n"):

pyproject.toml

@@ -42,7 +42,7 @@ pgp = ["gpg"]
 paramiko = ["paramiko"]
 dev = [
     "ruff==0.9.6",
-    "mypy==1.14.1"
+    "mypy==1.15.0"
 ]
 
 [project.scripts]