Update mypyc_attr supported keys list for weakref support (#15)

* Ignore .worktrees directory (#6)

* chore: sync AGENTS rules to keep contributor guidance consistent (#8)

* Update mypyc_attr supported keys test expectations

* Delete AGENTS.md

* Update .gitignore

Author: BobTheBuidler

mypyc/test-data/irbuild-classes.test

@@ -2927,11 +2927,11 @@ L0:
 from mypy_extensions import mypyc_attr
 
 @mypyc_attr("allow_interpreted_subclasses", "invalid_arg")  # E: "invalid_arg" is not a supported "mypyc_attr" \
-                                                            # N: supported keys: "allow_interpreted_subclasses", "free_list_len", "native_class", "serializable"
+                                                            # N: supported keys: "allow_interpreted_subclasses", "free_list_len", "native_class", "serializable", "supports_weakref"
 class InvalidArg:
     pass
 @mypyc_attr(invalid_kwarg=True)  # E: "invalid_kwarg" is not a supported "mypyc_attr" \
-                                 # N: supported keys: "allow_interpreted_subclasses", "free_list_len", "native_class", "serializable"
+                                 # N: supported keys: "allow_interpreted_subclasses", "free_list_len", "native_class", "serializable", "supports_weakref"
 class InvalidKwarg:
     pass
 @mypyc_attr(str())  # E: All "mypyc_attr" positional arguments must be string literals.