fix: failed importlib import (#254)

For some reason this failed in python310 with error
```
AttributeError: module 'importlib' has no attribute 'resources'
```

This fix _seems_ to work, although I'm not sure why it didn't work on
the first place...

tket2-py/tket2/passes.py

@@ -1,6 +1,6 @@
 from pathlib import Path
 from typing import Optional
-import importlib
+from importlib import resources
 
 from pytket import Circuit
 from pytket.passes import CustomPass
@@ -33,7 +33,7 @@ def badger_pass(
     The arguments `max_threads`, `timeout`, `log_dir` and `rebase` are optional
     and will be passed on to the Badger optimiser if provided."""
     if rewriter is None:
-        rewriter = Path(importlib.resources.files("tket2").joinpath("data/nam_6_3.rwr"))
+        rewriter = Path(resources.files("tket2").joinpath("data/nam_6_3.rwr"))
     opt = optimiser.BadgerOptimiser.load_precompiled(rewriter)
 
     def apply(circuit: Circuit) -> Circuit:

tket2-py/tket2/rewrite.py

@@ -3,7 +3,7 @@
 from .tket2 import _rewrite
 
 from pathlib import Path
-import importlib
+from importlib import resources
 
 __all__ = [
     "default_ecc_rewriter",
@@ -14,5 +14,5 @@
 def default_ecc_rewriter() -> _rewrite.ECCRewriter:
     """Load the default ecc rewriter."""
     # TODO: Cite, explain what this is
-    rewriter = Path(importlib.resources.files("tket2").joinpath("data/nam_6_3.rwr"))
+    rewriter = Path(resources.files("tket2").joinpath("data/nam_6_3.rwr"))
     return _rewrite.ECCRewriter.load_precompiled(rewriter)