BUG: is_dtype_equal(dtype, "string[pyarrow]") raises if pyarrow not installed
- [x] closes #44276
- [x] tests added / passed
- [x] Ensure all linting tests pass, see [here](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#pre-commit) for how to run them
- [x] whatsnew entry

Added instance to check string preventing import error

do we actually have a test which exercises this? e.g. not on a build where pyarrow is installed? > do we actually have a test which exercises this? e.g. not on a build where pyarrow is installed?

I do not have pyarrow running on my system and got the initial import error. Actually I am able to run this on a system where pyarrow is not installed. It does not matter as pyarrow is not imported, so installation will not matter. Whatsnew note added pls merge master as well Done, put the test into a new file as specified @jorisvandenbossche @jreback any updates for me on this? @jorisvandenbossche @jreback any updates for me on this? @shubham11941140 you need to merge master Done. Thanks @shubham11941140 