feat: allow rum=off to stabilize tests

[kptdobe]

Fix #217

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Commits

* [dedfd94](https://github.com/adobe/helix-rum-js/commit/dedfd94ce2b5b3425bd3242b4187a33b53a5fd52) :white_check_mark: (latest)

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 100.00%. Comparing base (6a912e9) to head (dedfd94). Report is 5 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #218 +/- ## ========================================= Coverage 100.00% 100.00% ========================================= Files 2 2 Lines 179 180 +1 ========================================= + Hits 179 180 +1 ```

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[adobe-bot]

:tada: This PR is included in version 2.7.0 :tada:

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

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