Replace deprecated command with environment file

[jongwooo]

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Fixes #154 🛠️

Update .github/workflows/sonar.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

run: echo "::set-output name=date::$(date +'%Y-%m-%d' --utc)"

TO-BE

run: echo "date=$(date +'%Y-%m-%d' --utc)" >> $GITHUB_OUTPUT

[sonarqubecloud]

Kudos, SonarCloud Quality Gate passed!   

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[lqiu96]

Thanks!