Chore: replace deprecated command with environment file

[jongwooo]

Description

Closes #44

Update .github/workflows/chart.yml to use environment file instead of deprecated set-output command.
For more information, see: https://github.blog/changelog/2022-10-11-github-actions-deprecating-save-state-and-set-output-commands/

I found the workflow file that use set-output command through the following command:

$ find . -name '*.yml' -o -name '*.yaml' | xargs egrep '\bset-output\b'

AS-IS

echo ::set-output name=TAG::${GITHUB_REF#refs/tags/}

TO-BE

echo "TAG::${GITHUB_REF#refs/tags/}" >> $GITHUB_OUTPUT

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (1ecdbb4) 83.74% compared to head (4dd42b7) 83.74%.

Additional details and impacted files

@@           Coverage Diff           @@
##           master      #45   +/-   ##
=======================================
  Coverage   83.74%   83.74%           
=======================================
  Files          36       36           
  Lines        1095     1095           
=======================================
  Hits          917      917           
  Misses        116      116           
  Partials       62       62           

Flag	Coverage Δ
unit-test	83.74% <ø> (ø)

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