[DependencyInjection] force ExpressionLanguage version >= 2.6

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #13176
| License       | MIT
| Doc PR        | 

The DependencyInjection component requires the ExpressionLanguage
component to be present in version 2.6 or higher to be able to use
expressions in service configurations since Symfony 2.6.