chore: Remove pytket dependency from tket-py

[aborgna-q]

After #1482 we no longer use pytket from the python side other than for type-checking PytketHugrPass and when testing.
Moved the dependency to a pytket extra. This is only required to have proper typing for the pass.

Now that pytket is not required to build and test the wheels, we can produce free-threaded wheels for python 3.13t (pytket doesn't publish those).
Edit: Removed the free-threaded wheels build.
I'll leave it for later, once hugr publishes 3.14t releases (Quantinuum/hugr#3021).

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 83.84%. Comparing base (042ba1d) to head (7477974).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1507   +/-   ##
=======================================
  Coverage   83.84%   83.84%           
=======================================
  Files         187      187           
  Lines       28959    28959           
  Branches    27880    27880           
=======================================
  Hits        24282    24282           
  Misses       3517     3517           
  Partials     1160     1160           

Flag	Coverage Δ
python	92.33% <100.00%> (ø)
qis-compiler	91.66% <ø> (ø)

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