ci: remove test retries

Test retries were added in https://github.com/pouchdb/pouchdb/pull/8433:

> We have been experiencing many flaky tests in our runs, an unknown cause for now.

Intermittent test failures should be documented and resolved. Once significant improvements have been made to test reliability, test retries should be removed.

* `9x`: https://github.com/pouchdb/pouchdb/issues/8690
* `8x`: https://github.com/pouchdb/pouchdb/issues/8689
* `7x`: https://github.com/pouchdb/pouchdb/issues/8691
* `6x`: https://github.com/pouchdb/pouchdb/issues/8693
* `6x`: https://github.com/pouchdb/pouchdb/issues/8695
* `3x`: https://github.com/pouchdb/pouchdb/issues/8694
* `2x`: https://github.com/pouchdb/pouchdb/issues/8701
* `1x`: https://github.com/pouchdb/pouchdb/issues/8696
* `1x`: https://github.com/pouchdb/pouchdb/issues/8697
* `1x`: https://github.com/pouchdb/pouchdb/issues/8698
* `1x`: https://github.com/pouchdb/pouchdb/issues/8699
* `1x`: https://github.com/pouchdb/pouchdb/issues/8700
* `1x`: https://github.com/pouchdb/pouchdb/issues/8702

These failures have been seen in the previous 14 :green_circle: `master` builds (as of 2023-06-26).