Allow using Pydantic v2

[ninoseki]

The latest version of FastAPI (v0.100.0) supports Pydantic v2.

• https://docs.pydantic.dev/2.0/

I'd like to use redis-om-python with Pydantic v2 while keeping the compatibility.

This PR does:

• Allow using Pydantic v2 (pydantic = ">=1.10.2,<2.1.0")
• Add _compat.py file to import proper Pydantic classes, etc.
  • Do from pydantic import ... if Pydantic is v1
  • Do from pydantic.v1 import ... if Pydantic is v2 (Note: Pydantic v2 contains v1 in v1 module)

It allows using Pydantic v2 along with redis-om-python.

[ninoseki]

There are lint & dependency audit errors.

I'm sure the lint error is out of the scope of this PR.

/home/runner/.local/bin/poetry run mypy ./tests/ aredis_om redis_om --ignore-missing-imports --exclude _compat\.py$
redis_om/model/cli/migrate.py:6: error: Argument 1 has incompatible type "Callable[[Any], Any]"; expected <nothing>
aredis_om/model/cli/migrate.py:6: error: Argument 1 has incompatible type "Callable[[Any], Any]"; expected <nothing>

I'm not sure about the audit error. Could you help me to fix the issue, please? (If this PR looks good)

[codecov-commenter]

Codecov Report

Patch coverage: 68.42% and project coverage change: -0.33 :warning:

Comparison is base (70f6401) 78.94% compared to head (099ca96) 78.61%.

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Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #533 +/- ## ========================================== - Coverage 78.94% 78.61% -0.33% ========================================== Files 14 15 +1 Lines 1178 1188 +10 ========================================== + Hits 930 934 +4 - Misses 248 254 +6 ``` | Flag | Coverage Δ | | |---|---|---| | unit | `78.61% <68.42%> (-0.33%)` | :arrow_down: | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=redis#carryforward-flags-in-the-pull-request-comment) to find out more. | [Impacted Files](https://app.codecov.io/gh/redis/redis-om-python/pull/533?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=redis) | Coverage Δ | | |---|---|---| | [aredis\_om/\_compat.py](https://app.codecov.io/gh/redis/redis-om-python/pull/533?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=redis#diff-YXJlZGlzX29tL19jb21wYXQucHk=) | `60.00% <60.00%> (ø)` | | | [aredis\_om/model/encoders.py](https://app.codecov.io/gh/redis/redis-om-python/pull/533?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=redis#diff-YXJlZGlzX29tL21vZGVsL2VuY29kZXJzLnB5) | `50.70% <100.00%> (-0.69%)` | :arrow_down: | | [aredis\_om/model/model.py](https://app.codecov.io/gh/redis/redis-om-python/pull/533?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=redis#diff-YXJlZGlzX29tL21vZGVsL21vZGVsLnB5) | `87.03% <100.00%> (-0.06%)` | :arrow_down: |

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[chayim]

@ninoseki I've merged master in accordingly.

[ninoseki]

Thanks and please let me know if I need additional works on this PR.

[chayim]

given the opt in nature - and the pydantic changes.. it seems very clean.