`pydantic.color.Color` is not hashable in 1.10.0 release

[Czaki]

Initial Checks

• I have searched GitHub for a duplicate issue and I'm sure this is something new
• I have searched Google & StackOverflow for a solution and couldn't find anything
• I have read and followed the docs and still think this is a bug
• I am confident that the issue is with pydantic (not my code, or another library in the ecosystem like FastAPI or mypy)

Description

In pydantic 1.9.2 (and earlier), the Color class was Hashable. in release 1.10.0 it is not hashable that broke usage color as an argument to function decorated with @lru_cache from std lib. (napari/napari#4995)

A I do not see public method for mutate such object IO thin that it is deprecation.

Example Code

pydantic 1.9.2

In [1]: from pydantic.color import Color                                                     

In [2]: a = Color((0,0,0))                                                                   

In [3]: hash(a)                                                                              
Out[3]: 8771047785283

pydantic 1.10.0

In [1]: from pydantic.color import Color                                                     

In [2]: a = Color((0,0,0))                                                                   

In [3]: hash(a)                                                                              
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-3-57b555d30865> in <module>
----> 1 hash(a)

TypeError: unhashable type: 'Color'

### Python, Pydantic & OS Version

```Text
pydantic 1.9.2 vs pydantic 1.10.0 tested on ubuntu and macos m1.

Affected Components

• Compatibility between releases
• Data validation/parsing
• Data serialization - .dict() and .json()
• JSON Schema
• Dataclasses
• Model Config
• Field Types - adding or changing a particular data type
• Function validation decorator
• Generic Models
• Other Model behaviour - construct(), pickling, private attributes, ORM mode
• Settings Management
• Plugins and integration with other tools - mypy, FastAPI, python-devtools, Hypothesis, VS Code, PyCharm, etc.

[samuelcolvin]

Thanks so much for reporting, I've added napari to #4359.

Confirmed. Seems this was an unexpected side effect of #3646 I didn't know that adding __eq__ brakes hashing.

PR welcome to fix this, otherwise I'll do it soon.

[Czaki]

I just found it here (second paragraph): https://docs.python.org/3/reference/datamodel.html#object.__hash__, but also do not know earlier.