Bump symfony/flex from 1.2.0 to 1.2.1
Bump symfony/flex from 1.2.0 to 1.2.1

Bumps [symfony/flex](https://github.com/symfony/flex) from 1.2.0 to 1.2.1.
- [Release notes](https://github.com/symfony/flex/releases)
- [Commits](https://github.com/symfony/flex/compare/v1.2.0...v1.2.1)

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
alcohol/paste.robbast.nl,alcohol/paste.robbast.nl,alcohol/paste.robbast.nl,alcohol/sf-minimal-demo