ci: Skip status check on docs changed

[evenyag]

I hereby agree to the terms of the GreptimeDB CLA

What's changed and what's your intention?

Marks the required status check as passed when the PR only changes files in the ignored path. It also moves the coverage test to the develop.yml so it can use the same action name CI.

See handling-skipped-but-required-checks

Checklist

• I have written the necessary rustdoc comments.
• I have added the necessary unit tests and integration tests.

Refer to a related PR or issue link (optional)

[codecov]

Codecov Report

Merging #903 (a466e1e) into develop (43aefc5) will decrease coverage by 0.12%.
The diff coverage is n/a.

@@             Coverage Diff             @@
##           develop     #903      +/-   ##
===========================================
- Coverage    86.27%   86.15%   -0.12%     
===========================================
  Files          427      427              
  Lines        57529    57529              
===========================================
- Hits         49632    49565      -67     
- Misses        7897     7964      +67     

Flag	Coverage Δ
rust	86.15% <ø> (-0.12%)	⬇️

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

Impacted Files	Coverage Δ
src/object-store/src/test_util.rs	0.00% <0.00%> (-100.00%)	⬇️
src/datanode/src/instance.rs	49.76% <0.00%> (-15.79%)	⬇️
tests-integration/src/test_util.rs	87.55% <0.00%> (-11.99%)	⬇️
src/common/substrait/src/types.rs	50.96% <0.00%> (-0.97%)	⬇️
src/frontend/src/table/scan.rs	90.74% <0.00%> (+5.55%)	⬆️

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[evenyag]

Experimenting with #836 , don't merge this please

[v0y4g3r]

LGTM

[fengjiachun]

lgtm