Fix - Cannot parse Greek characters (and possibly others) in parse_mathematica

[yvestumushimire]

Fix Cannot parse Greek characters (and possibly others) in parse_mathematica

References to other Issues or PRs

Fixes #24055

Brief description of what is fixed or changed

Skipping non ascii letters in tokeneziner.findall()

Other comments

Release Notes

• parsing
  • Fix a bug with parsing Greek characters (and possibly others)

[sympy-bot]

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• parsing
  • Fix a bug with parsing Greek characters (and possibly others) (#24102 by @yvestumushimire)

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Fix Cannot parse Greek characters (and possibly others) in parse_mathematica

#### References to other Issues or PRs
Fixes #24055 

#### Brief description of what is fixed or changed
Skipping non ascii letters in `tokeneziner.findall()`

#### Other comments


#### Release Notes

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* solvers
  * Added a new solver for logarithmic equations.

* functions
  * Fixed a bug with log of integers.

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<!-- BEGIN RELEASE NOTES -->
* parsing
  *  Fix a bug with parsing Greek characters (and possibly others)
<!-- END RELEASE NOTES -->

Update

The release notes on the wiki have been updated.

[github-actions]

Benchmark results from GitHub Actions

Lower numbers are good, higher numbers are bad. A ratio less than 1
means a speed up and greater than 1 means a slowdown. Green lines
beginning with + are slowdowns (the PR is slower then master or
master is slower than the previous release). Red lines beginning
with - are speedups.

Significantly changed benchmark results (PR vs master)

Significantly changed benchmark results (master vs previous release)

       before           after         ratio
     [41d90958]       [58598660]
     <sympy-1.11.1^0>                 
+     1.19±0.06ms      1.84±0.07ms     1.54  solve.TimeRationalSystemSymbol.time_solve(1)
-     3.21±0.03ms      1.53±0.03ms     0.48  solve.TimeSparseSystem.time_linear_eq_to_matrix(20)
-     6.42±0.07ms       2.20±0.1ms     0.34  solve.TimeSparseSystem.time_linear_eq_to_matrix(30)

Full benchmark results can be found as artifacts in GitHub Actions
(click on checks at the top of the PR).

[oscarbenjamin]

Looks good. Thanks!