Constrain bitstring to bitarray<3.0

[akrherz]

Checklist

• Used a static YAML file for the patch if possible (instructions).
• Only wrote code directly into generate_patch_json.py if absolutely necessary.
• Ran pre-commit run -a and ensured all files pass the linting checks.
• Ran python show_diff.py and posted the output as part of the PR.
• Modifications won't affect packages built in the future.

refs conda-forge/bitstring-feedstock#15

With bitarray=3.0 on conda-forge, the dep solver will find an older bitstring that had an open ended dep on bitarray>=2.8

$ python show_diff.py
================================================================================
================================================================================
linux-armv7l
================================================================================
================================================================================
win-32
================================================================================
================================================================================
linux-ppc64le
================================================================================
================================================================================
osx-arm64
================================================================================
================================================================================
linux-aarch64
================================================================================
================================================================================
noarch
noarch::bitstring-4.1.0-pyhd8ed1ab_0.conda
-    "bitarray >=2.8.0",
+    "bitarray >=2.8.0,<3",
================================================================================
================================================================================
win-64
================================================================================
================================================================================
osx-64
================================================================================
================================================================================
linux-64

cc: @conda-forge/bitstring

[conda-forge-admin]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipe/meta.yaml) and found it was in an excellent condition.