TiUP: update --self add some checks.

[srstack]

What problem does this PR solve?

close #1693

What is changed and how it works?

tiup update --self
Backup of `/Users/srstack/.tiup/bin/tiup` to `/Users/srstack/.tiup/bin/tiup.tmp` failed.
Error: rename /Users/srstack/.tiup/bin/tiup /Users/srstack/.tiup/bin/tiup.tmp: no such file or directory

to

tiup update --self
Tiup install directory is: /opt/homebrew/Cellar/tiup/v1.8.1/bin
Error: If you used some external package manager to install TiUP (e.g., brew), try upgrade with that

Check List

Tests

• Manual test (add detailed scripts or steps below)

Code changes

Side effects

Related changes

Release notes:

NONE

[ti-chi-bot]

[REVIEW NOTIFICATION]

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• nexustar

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[codecov-commenter]

Codecov Report

Merging #1695 (08d2aaf) into master (be07156) will decrease coverage by 5.68%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##           master    #1695      +/-   ##
==========================================
- Coverage   47.88%   42.21%   -5.68%     
==========================================
  Files         301      301              
  Lines       33993    34011      +18     
==========================================
- Hits        16277    14355    -1922     
- Misses      15603    17741    +2138     
+ Partials     2113     1915     -198     

Flag	Coverage Δ
cluster	32.71% <ø> (-8.78%)	⬇️
dm	24.80% <ø> (-0.05%)	⬇️
playground	12.78% <ø> (ø)
tiup	14.66% <0.00%> (+0.01%)	⬆️
unittest	∅ <ø> (∅)

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

Impacted Files	Coverage Δ
cmd/update.go	37.80% <0.00%> (-10.63%)	⬇️
pkg/cluster/operation/systemd.go	0.00% <0.00%> (-75.00%)	⬇️
pkg/cluster/manager/check.go	0.00% <0.00%> (-69.81%)	⬇️
pkg/cluster/task/limits.go	0.00% <0.00%> (-65.22%)	⬇️
pkg/cluster/task/sysctl.go	0.00% <0.00%> (-63.64%)	⬇️
pkg/cluster/manager/cleanup.go	0.00% <0.00%> (-57.92%)	⬇️
pkg/cluster/template/config/alertmanager.go	0.00% <0.00%> (-55.00%)	⬇️
pkg/cluster/task/copy_file.go	0.00% <0.00%> (-52.94%)	⬇️
pkg/cluster/operation/check.go	0.00% <0.00%> (-50.46%)	⬇️
pkg/cluster/task/rmdir.go	0.00% <0.00%> (-46.67%)	⬇️
... and 75 more

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[AstroProfundis]

I think it's better to say "If you used some external package manager to install TiUP (e.g., brew), try upgrade with that." as brew is not the only way a user may get TiUP without our script.

[AstroProfundis]

/merge

[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Commit hash: 08d2aaf