What kind of change does this PR introduce?

Feature

What is the current behavior?

Tested up to DotNet 7

What is the new behavior?

Tested up to DotNet 8

What might this PR break?

DotNet 6+ targets have been changed to NetStandard 2.1 to allow the support for DotNet 8

Please check if the PR fulfills these requirements

• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

Other information: