fix: Add Oracle Linux 2 as supported OS

[srstack]

What problem does this PR solve?

Add Oracle Linux 2 as supported OS

Check List

Tests

• Manual test (add detailed scripts or steps below)

Release notes:

NONE

[ti-chi-bot]

[REVIEW NOTIFICATION]

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• nexustar

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[codecov-commenter]

Codecov Report

Merging #1786 (30fc81a) into master (b2ed8aa) will decrease coverage by 0.22%.
The diff coverage is 0.00%.

❗ Current head 30fc81a differs from pull request most recent head f68f2d4. Consider uploading reports for the commit f68f2d4 to get more accurate results

@@            Coverage Diff             @@
##           master    #1786      +/-   ##
==========================================
- Coverage   53.08%   52.86%   -0.22%     
==========================================
  Files         303      303              
  Lines       34624    34587      -37     
==========================================
- Hits        18379    18282      -97     
- Misses      14084    14150      +66     
+ Partials     2161     2155       -6     

Flag	Coverage Δ
cluster	41.07% <0.00%> (-0.30%)	⬇️
dm	24.82% <0.00%> (-0.06%)	⬇️
tiup	14.40% <ø> (ø)
unittest	21.29% <ø> (ø)

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

Impacted Files	Coverage Δ
pkg/cluster/operation/check.go	48.44% <0.00%> (ø)
pkg/cluster/template/config/alertmanager.go	0.00% <0.00%> (-55.00%)	⬇️
pkg/utils/retry.go	46.43% <0.00%> (-16.07%)	⬇️
pkg/cluster/spec/tikv.go	55.74% <0.00%> (-6.89%)	⬇️
pkg/cluster/audit/audit.go	38.84% <0.00%> (-4.74%)	⬇️
pkg/utils/ioutil.go	60.09% <0.00%> (-4.60%)	⬇️
pkg/cluster/spec/alertmanager.go	65.22% <0.00%> (-2.17%)	⬇️
pkg/cluster/api/pdapi.go	57.35% <0.00%> (-2.12%)	⬇️
pkg/cluster/spec/server_config.go	70.72% <0.00%> (-0.90%)	⬇️
components/dm/command/audit.go	59.38% <0.00%> (+1.80%)	⬆️
... and 2 more

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[srstack]

/merge

[ti-chi-bot]

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

Commit hash: f68f2d4