[Security] Bump pyopenssl from 17.3.0 to 18.0.0 (#1151)
[Security] Bump pyopenssl from 17.3.0 to 18.0.0 (#1151)

Bumps [pyopenssl](https://github.com/pyca/pyopenssl) from 17.3.0 to 18.0.0. **This update includes security fixes.**
- [Release notes](https://github.com/pyca/pyopenssl/releases)
- [Changelog](https://github.com/pyca/pyopenssl/blob/master/CHANGELOG.rst)
- [Commits](https://github.com/pyca/pyopenssl/compare/17.3.0...18.0.0)

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
ebmdatalab/openprescribing,ebmdatalab/openprescribing,ebmdatalab/openprescribing,annapowellsmith/openpresc,ebmdatalab/openprescribing,annapowellsmith/openpresc,annapowellsmith/openpresc,annapowellsmith/openpresc