update codecov configuration

[saintube]

Ⅰ. Describe what this PR does

enable coverage diff check by adding a codecov.yaml

Ⅱ. Does this pull request fix one issue?

#124

Ⅲ. Describe how to verify it

check if CI fails when coverage diff is low

Ⅳ. Special notes for reviews

none

[codecov-commenter]

Codecov Report

Merging #131 (7e36cb4) into main (d6de2aa) will decrease coverage by 0.34%.
The diff coverage is 0.00%.

❗ Current head 7e36cb4 differs from pull request most recent head 5edd67e. Consider uploading reports for the commit 5edd67e to get more accurate results

@@            Coverage Diff             @@
##             main     #131      +/-   ##
==========================================
- Coverage   57.68%   57.33%   -0.35%     
==========================================
  Files          90       78      -12     
  Lines        8056     7376     -680     
==========================================
- Hits         4647     4229     -418     
+ Misses       3004     2765     -239     
+ Partials      405      382      -23     

Flag	Coverage Δ
unittests	57.33% <0.00%> (-0.35%)	⬇️

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

Impacted Files	Coverage Δ
pkg/util/pod.go	10.00% <0.00%> (ø)
pkg/koordlet/statesinformer/api.go	0.00% <0.00%> (-100.00%)	⬇️
pkg/koordlet/reporter/config.go	0.00% <0.00%> (-66.67%)	⬇️
pkg/koordlet/statesinformer/config.go	0.00% <0.00%> (-58.34%)	⬇️
pkg/koordlet/statesinformer/kubelet_stub.go	0.00% <0.00%> (-35.30%)	⬇️
pkg/koordlet/statesinformer/states_informer.go	8.21% <0.00%> (-27.50%)	⬇️
...slo-controller/nodemetric/nodemetric_controller.go	53.19% <0.00%> (-7.39%)	⬇️
pkg/koordlet/reporter/reporter.go	1.92% <0.00%> (-4.72%)	⬇️
pkg/koordlet/config/config.go	69.23% <0.00%> (-3.19%)	⬇️
pkg/util/system/util_test_tool.go	53.33% <0.00%> (-2.85%)	⬇️
... and 19 more

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[saintube]

/hold

[saintube]

/hold cancel

[hormes]

/lgtm
/approve

[koordinator-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: hormes

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