removing dead code.
minor #10219 [EventDispatcher] removing dead code. (inalgnu)

This PR was submitted for the 2.3-dev branch but it was merged into the 2.3 branch instead (closes #10219).

Discussion
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[EventDispatcher] removing dead code.

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

Commits
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e28395f [EventDispatcher] removing dead code.