ci: use env file instead of set_output

[iisakkirotko]

Although the removal of set_output has been delayed, it will still likely happen at some point. See https://github.blog/changelog/2022-10-11-github-actions-deprecating-save-state-and-set-output-commands/ for details

[iisakkirotko]

• #583
• #582
• #579 👈
• #578
• master

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[iisakkirotko]

Merge activity

• Apr 5, 8:21 AM EDT: @iisakkirotko started a stack merge that includes this pull request via Graphite.
• Apr 5, 8:23 AM EDT: Graphite rebased this pull request as part of a merge.
• Apr 5, 8:24 AM EDT: @iisakkirotko merged this pull request with Graphite.

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