Bump VERSION to 10.0.0

• Diff: https://gitlab.com/gitlab-org/gitlab-qa/compare/v9.1.2...3af7865d

• Release notes:

### New scenarios and scenario updates

- !1142 Improvements for Test::Integration::Import scenario type.
- !1146 Remove superseded update job type.
- !1148 Add scenario for GitHub OAuth

### Fixes

- !1139 Disable protected env check for schema load task.
- !1151 Include ee in spec path

### Doc changes

- !1147 Update readme with foss links.

### Other changes (CI, backstage)

- !1132 Prevent spam creation of failure issues.
- !1141 Update gitlab_spec to reduce brittleness.
- !1143 Remove package-and-test pipeline setup.
- !1144 Fix default ci pipeline rule.
- !1145 Populate bundle cache on e2e runners and some improvements.
- !1151 Include `ee` in spec path.

• Checklist before merging:

  • Diff link is up-to-date.
  • Based on the diff, lib/gitlab/qa/version.rb is updated, according to SemVer.
  • Release notes are accurate.

• Checklist after merging:

  • Update the release notes for the newly created tag.