Replace isort and flake8 with Ruff checker

[mwtoews]

This PR replaces isort and flake8 lint tools with Ruff check tools. The rational is that Ruff is very fast, which has earned it's recent popularity. It also has Drop-in parity with flake8, isort, and Black.

With the transition, the old configurations are mapped to new configurations. Some of these were redundant or some ignores have no effect, so are not transitioned.

This PR does not replace Black with Ruff format, as this would incur more changed files (I'm seeking for minimal changes to source files). But a follow-up PR can replace Black with Ruff format, with the updated source files.

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 75.00000% with 1 line in your changes missing coverage. Please review.

Project coverage is 82.01%. Comparing base (f9ea1a0) to head (e22bffa).
Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
keras/src/models/model.py	50.00%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##           master   #20442   +/-   ##
=======================================
  Coverage   82.01%   82.01%           
=======================================
  Files         514      514           
  Lines       47183    47192    +9     
  Branches     7409     7408    -1     
=======================================
+ Hits        38697    38706    +9     
  Misses       6696     6696           
  Partials     1790     1790           

Flag	Coverage Δ
keras	81.87% <75.00%> (+<0.01%)	⬆️
keras-jax	64.92% <75.00%> (+<0.01%)	⬆️
keras-numpy	59.87% <75.00%> (+<0.01%)	⬆️
keras-tensorflow	65.92% <75.00%> (+<0.01%)	⬆️
keras-torch	64.87% <75.00%> (+<0.01%)	⬆️

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[fchollet]

Thanks for the PR! We can definitely consider this change. Please take a look at the code format check failure.

[mwtoews]

The rational is that Ruff is very fast

Looking at the speedup via time bash shell/lint.sh (and commenting out black ...) the results in master are:

$ time bash shell/lint.sh
...
real	0m3.153s
user	0m29.378s
sys	0m0.430s

and with this PR are significantly faster:

$ time bash shell/lint.sh
...
real	0m0.030s
user	0m0.029s
sys	0m0.053s

[fchollet]

LGTM, thank you