Updated availability with correct % and removed needs attention from cost saving

Why is this change being made?

In !128051 (diffs) availability was incorrectly reported as 90% due to the GitLab bot changing scores based on sub objectives and results of https://gitlab.com/gitlab-com/gitlab-OKRs/-/work_items/2192. The correct score is 99.95% rounded down to 99% because rounding up would create the wrong perception.

Additionally I've removed needs attention from the cost saving Key Result because 5% was highly aspirational and the achievement of 60% of a highly aspirational goal should not need attention. This label will be demoralising for the team given the challenging work and trade offs to achieve this.

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