Replace unsafe yaml.load() with yaml.safe_load() in static binding generators

[coderabbitai]

Summary

Replace all usages of yaml.load(..., yaml.Loader) with yaml.safe_load() to avoid potential arbitrary code execution when parsing user-supplied config files.

Affected locations

• numbast/src/numbast/tools/static_binding_generator.py — at least 2 call sites (including _cfg_path_uses_mlir_backend and Config.from_yaml_path)
• numbast/src/numbast/experimental/mlir/tools/static_binding_generator.py — at least 2 call sites

Suggested fix

Replace each occurrence:

# Before
config_dict = yaml.load(f, yaml.Loader)

# After
config_dict = yaml.safe_load(f)

yaml.safe_load() is already used elsewhere in the codebase (e.g., in the YAML schema/docs tests), so this is a straightforward consistency fix.

References

• Flagged during review of PR Migrate experimental MLIR backend #346: Migrate experimental MLIR backend #346 (comment)
• Requested by @isVoid