Added deprecation log for validate and validateValue on ExecutionContext...

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | yes
| Tests pass?   | yes
| Fixed tickets | #12685
| License       | MIT
| Doc PR        | 

Can you move the whole expression on one line instead? Thanks.