minor #17398 [Validator] remove obsolete context and PropertyAccess code (Tobion)

This PR was squashed before being merged into the 3.0 branch (closes #17398).

Discussion
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[Validator] remove obsolete context and PropertyAccess code

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | -
| License       | MIT
| Doc PR        | -

Commits
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a9d9d62 [Validator] remove obsolete context and PropertyAccess code

Author: fabpot

Resources/config/validator.xml

@@ -44,7 +44,6 @@
         </service>
 
         <service id="validator.expression" class="Symfony\Component\Validator\Constraints\ExpressionValidator">
-            <argument type="service" id="property_accessor" />
             <tag name="validator.constraint_validator" alias="validator.expression" />
         </service>