fix: board reaction spam leading to misplacement

[Schwehn42]

Description

Spamming many board reactions would lead to them being displayed below the board, creating a scrollbar.
This has been fixed. Closes #4082.

Changelog

• BoardReactionMenu: Change container position to from absolute to fixed

How to test this:

I used the following code to test this locally:

useEffect(() => {
    setInterval(() => dispatch(Actions.addBoardReaction("heart")), 25);
  }, []);

[octomind-dev]

🐙 Octomind

Test Report: 0/14 successful.

description	status	details
About Section Visibility Test	Failed ❌	click
change avatar	Failed ❌	click
check Privacy Policy	Failed ❌	click
check terms & conditions	Failed ❌	click
close cookie banner - front page	Failed ❌	click
close cookie banner - sign-in	Failed ❌	click
create and delete board columns	Failed ❌	click
create_and_delete_notes_and_actions_v2	Failed ❌	click
create lean coffee board	Failed ❌	click
edit_notes_and_actions_v5	Failed ❌	click
get started	Failed ❌	click
share_session	Failed ❌	click
sign-in	Failed ❌	click
test all ways to open the setup flow	Failed ❌	click

commit sha: d458a8a

[github-actions]

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Deployed Images

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• ghcr.io/inovex/scrumlr.io/scrumlr-server:sha-719113c

[octomind-dev]

🐙 Octomind

Test Report: 11/14 successful.

description	status	details
About Section Visibility Test	Passed ✅	click
change avatar	Passed ✅	click
check Privacy Policy	Passed ✅	click
check terms & conditions	Passed ✅	click
close cookie banner - front page	Passed ✅	click
close cookie banner - sign-in	Passed ✅	click
create and delete board columns	Failed ❌	click
create_and_delete_notes_and_actions_v2	Passed ✅	click
create lean coffee board	Failed ❌	click
edit_notes_and_actions_v5	Passed ✅	click
get started	Passed ✅	click
share_session	Passed ✅	click
sign-in	Passed ✅	click
test all ways to open the setup flow	Failed ❌	click

commit sha: 719113c