remove extra hx-swap-oob attribute that is not used in the page

[MichaelWest22]

Description

hx-swap-oob attribute is making its way onto the page/dom after ture/outerHTML oob swaps. They are not needed or used on the page and just add confusion so i've added two lines to remove them from the swapped in content during oobSwap()

Corresponding issue:
#2822

Testing

Wrote a couple of tests to make sure the tags were removed and found one test was broken by my change which I had to update. Also tested it on my test application to make sure the tags were not seen in the page after swaps.

Checklist

• I have read the contribution guidelines
• I have targeted this PR against the correct branch (master for website changes, dev for
  source changes)
• This is either a bugfix, a documentation update, or a new feature that has been explicitly
  approved via an issue
• I ran the test suite locally (npm run test) and verified that it succeeded