Remove support to use `&` as alias for `AND` with tag patterns

[pekkaklarck]

See #5661 for reasoning why & was deprecated in RF 7.5 and why it can be removed in RF 8.0. See also #5656 for another tag pattern related change.

[sudheerr937-ai]

Hi @pekkaklarck
I'd like to work on this issue. I've reviewed the deprecation commit c064b22 from #5661 and understand that the fix involves removing the & alias block from TagPattern.from_string() in src/robot/model/tags.py, along with updating the related test and documentation files. Could you please assign this issue to me?

[sudheerr937-ai]

Hi @pekkaklarck,

I have raised a PR for this issue. Here is the summary of changes made:

1.Removed & handling block from TagPattern.from_string() in src/robot/model/tags.py
2.Removed test_ampersand_is_deprecated unit test from utest/model/test_tags.py
3.Removed Deprecated & operator test cases from acceptance tests in include_and_exclude.robot and include_and_exclude_with_rebot.robot
4.Simplified Validate deprecated operator warning keyword by removing the & specific IF/ELSE branch
5.Removed outdated note about & from BasicUsage.rst documentation

All 56 unit tests are passing locally. Please review when you get a chance!

[pekkaklarck]

The PR looks pretty good, but due to this issue being targeted for RF 8, it cannot be merged in the near future.