Fix regression in test_graph_manipulation

[crusaderky]

Fix regression introduced in #10865, appearing in dask_expr only.
The above PR changes tokenization of bound methods from

• pickle of the whole instance plus method name

to

• tokenization of the instance plus method name

and tokenization of generic objects does not attempt to pickle (by design).

[phofl]

rebased after all the noise is gone in the dask-expr ci

[github-actions]

Unit Test Results

See test report for an extended history of previous test failures. This is useful for diagnosing flaky tests.

     15 files       15 suites   3h 18m 46s ⏱️
 12 981 tests  12 048 ✅    929 💤 4 ❌
160 144 runs  143 562 ✅ 16 577 💤 5 ❌

For more details on these failures, see this check.

Results for commit 2c61fbd.

[phofl]

only int and float hashing now left