ci: Upgrade actions/upload-artifact to v3

[pevik]

This fixes error in CI:

Error: This request has been automatically failed because it uses a deprecated version of actions/upload-artifact: v2.

[coveralls]

coverage: 87.614%. remained the same when pulling 07d99e4d66491784b6ced4b9fad910a9901165c2 on pevik:fix-ci into b32852cc8a644fea3c9b03294b17c2b930d909f7 on schweikert:develop.

[schweikert]

Thanks!