Update target framework - replace net5.0 with net6.0

[fszlin]

Description

• Update target framework to net6.0
• Switch integration tests to pebble

Checklist

• [x] All tests are passing
• [x] New tests were created to address changes in pr (and tests are passing)
• [x] Updated README and/or documentation, if necessary

[codecov[bot]]

Codecov Report

Merging #302 (b2fa810) into main (417513f) will decrease coverage by 0.25%. The diff coverage is 33.33%.

:exclamation: Current head b2fa810 differs from pull request most recent head dea3fee. Consider uploading reports for the commit dea3fee to get more accurate results

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #302 +/- ## ========================================== - Coverage 92.54% 92.28% -0.26% ========================================== Files 89 89 Lines 2722 2734 +12 Branches 146 146 ========================================== + Hits 2519 2523 +4 - Misses 185 191 +6 - Partials 18 20 +2 ```