BUG: creating dataframe from masked numpy array turns missing string …
…values into NaN

- [x] closes #54706 (Replace xxxx with the GitHub issue number)
- [x] [Tests added and passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#writing-tests) if fixing a bug or adding a new feature
- [ ] All [code checks passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#pre-commit).
- [ ] Added [type annotations](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#type-hints) to new arguments/methods/functions.
- [ ] Added an entry in the latest `doc/source/whatsnew/vX.X.X.rst` file if fixing a bug or adding a new feature.

take
 Could you address the failing tests? @jbrockmendel Hi I am facing some issue while testing the code with the following

 ` # GH#18463
            warnings.warn(
                f"Mismatched null-like values {a} and {b} found. In a future "
                "version, pandas equality-testing functions "
                "(e.g. assert_frame_equal) will consider these not-matching "
                "and raise.",
                FutureWarning,
                stacklevel=find_stack_level()`
                
                
causing the test to fail while running 
                
 `pytest pandas/tests/series/test_constructors.py`
 
 
 it has been 10 days but there has been no response on slack regarding the query. Kindly help  > [...] causing the test to fail while running
>
> pytest pandas/tests/series/test_constructors.py

That generally means you are doing something like `tm.assert_series_equal(result, expected)` and result/expected contain different NA-like values, e.g. one has `np.nan` while the other has `None`.  To avoid the warning, they need to match. This pull request is stale because it has been open for thirty days with no activity. Please [update](https://pandas.pydata.org/pandas-docs/stable/development/contributing.html#updating-your-pull-request) and respond to this comment if you're still interested in working on this. Thanks for the pull request, but it appears to have gone stale. If interested in continuing, please merge in the main branch, address any review comments and/or failing tests, and we can reopen.