[TECH DEBT] Deprecate salt/utils/odict.py

[dwoz]

• Why Deprecate salt/utils/odict.py

• Python ≥3.7 preserves insertion order in plain dict, and collections.OrderedDict remains available for edge cases, so our bespoke wrapper no longer provides unique behavior.
• The module duplicating DefaultOrderedDict/HashableOrderedDict adds maintenance and import overhead; moving these helpers into salt.utils.datastructures gives them a clearer home while keeping the API.
• Loader profiling showed each odict.OrderedDict carries extra linked-list payload and import bookkeeping; using stdlib types trims memory and speeds module scans.
• Dropping salt.utils.odict simplifies the dependency graph (fewer Salt-specific imports in execution/state modules and tests), making code easier to read and align with third-party expectations.