Add instructions on how to yank a flytectl release

[eapolinario]

Why are the changes needed?

We had an incident yesterday (explained in #6100) caused by a bad version of flytectl, but we didn't have explicit instructions on how to yank the faulty flytectl version.

What changes were proposed in this pull request?

Add instructions on how to yank flytectl from homebrew and from the install.sh script.

How was this patch tested?

Setup process

Screenshots

Check all the applicable boxes

• I updated the documentation accordingly.
• All new and existing tests passed.
• All commits are signed-off.

Related PRs

Docs link

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 36.98%. Comparing base (2a7d363) to head (aace303).
Report is 2 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #6105      +/-   ##
==========================================
- Coverage   36.98%   36.98%   -0.01%     
==========================================
  Files        1318     1318              
  Lines      132406   132439      +33     
==========================================
+ Hits        48974    48980       +6     
- Misses      79179    79206      +27     
  Partials     4253     4253              

Flag	Coverage Δ
unittests-datacatalog	51.58% <ø> (ø)
unittests-flyteadmin	54.06% <ø> (-0.02%)	⬇️
unittests-flytecopilot	30.99% <ø> (ø)
unittests-flytectl	62.29% <ø> (ø)
unittests-flyteidl	7.23% <ø> (-0.01%)	⬇️
unittests-flyteplugins	53.82% <ø> (ø)
unittests-flytepropeller	42.60% <ø> (ø)
unittests-flytestdlib	55.18% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.