Annotated count fix index error

[Chr0nos]

Description

Motivation and Context

It fixes a 4 year old bug, when creating an annotation that has no matches, the result is an empty list but the actual code tries to reach for result[0] causing an IndexError

#469

How Has This Been Tested?

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added the changelog accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

[abondar]

Hi!

Please do not bump version in pyproject, I will do it myself of release

Can you please rebase on new develop, previous commit had faulty version of mssql there, so CI was failing

Also - would be great if you could add testcase, that demonstrates fixed behaviour

[Chr0nos]

Hi!
just rebased now and removed the version bump, i'l try to add the testcase this weekend 👍

[coveralls]

Pull Request Test Coverage Report for Build 11232041104

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

• For more information on this, see Tracking coverage changes with pull request builds.
• To avoid this issue with future PRs, see these Recommended CI Configurations.
• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

• 2 of 2 (100.0%) changed or added relevant lines in 1 file are covered.
• 38 unchanged lines in 3 files lost coverage.
• Overall coverage decreased (-0.005%) to 89.006%

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Files with Coverage Reduction	New Missed Lines	%
tortoise/backends/mysql/executor.py	2	95.74%
tortoise/filters.py	10	91.3%
tortoise/contrib/pylint/init.py	26	0.0%

Totals
Change from base Build 11048931810:	-0.005%
Covered Lines:	5975
Relevant Lines:	6598

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💛 - Coveralls

[Chr0nos]

Hi, i added the test that show what the fix is about, sorry for the response time