build: Use GITHUB_ENV instead of set-env
https://github.blog/changelog/2020-10-01-github-actions-deprecating-set-env-and-add-path-commands/
Action and workflow authors who are setting environment variables via stdout should update any usage of the set-env and add-path workflow commands to use the new environment files.
Checklist
-
make -j4 test
(UNIX), orvcbuild test
(Windows) passes -
tests and/or benchmarks are included -
documentation is changed or added -
commit message follows commit guidelines