BREAKING CHANGE: Bumped ethers version from v5.4.0 to v6.7.1


* feat: bump ethers to v6.7.1

* wip: bump

* wip: bump

* fix: updated hardhat tests for v6

* fix: remove test.js files

* fix: somewhat working

* fix: bump ci node version

* fix: restore test:js

* fix: use hardhat.config for outDir

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Co-authored-by: osslgtm <68947167+osslgtm@users.noreply.github.com>