Which @angular/* package(s) are the source of the bug?

animations

Is this a regression?

Yes

Description

When an @Output() or output() EventEmitter property name starts with the string "animate", Angular incorrectly triggers its animations subsystem during component updates, causing a runtime error.

Reproduction:
in a component name an output() or @ Output() animateXYZ
bind to this output in a template (doesn't matter if it is conditionally rendered or not)
check console when component is rendered

Error Message:
Component update failed: ASSERTION ERROR: Expected ElementRegistry to be present in animations subsystem [Expected=> null != undefined <=Actual]
Expected Behavior:
EventEmitter names starting with "animate" should work normally without triggering the animations subsystem.

Actual Behavior:
Runtime error occurs when the component with the EventEmitter starting with "animate" is rendered.

Additional Context:
This appears to be a regression introduced in Angular 20.2 (no runtime error in 20.1.8). The issue seems to be related to Angular incorrectly identifying component properties as animation-related based on naming patterns.

Please provide a link to a minimal reproduction of the bug

https://stackblitz.com/edit/repro-jbkqpft2?file=package.json

Please provide the exception or error you saw

ERROR Error: ASSERTION ERROR: Expected `ElementRegistry` to be present in animations subsystem [Expected=> null != undefined <=Actual]
    at throwError2 (root_effect_scheduler.mjs:351:11)
    at assertDefined (root_effect_scheduler.mjs:347:9)
    at Module.ɵɵanimateLeaveListener (debug_node.mjs:22232:9)
    at App_Conditional_7_Template (app.ts:13:30)
    at executeTemplate (debug_node.mjs:7939:9)
    at renderView (debug_node.mjs:8555:13)
    at createAndRenderEmbeddedLView (debug_node.mjs:8625:9)
    at Module.ɵɵconditional (debug_node.mjs:22854:39)
    at App_Template (app.ts:12:17)
    at executeTemplate (debug_node.mjs:7939:9)

Please provide the environment you discovered this bug in (run ng version)

Angular: 20.2.2
... common, compiler, compiler-cli, core, forms
... platform-browser, router

Package                      Version
------------------------------------
@angular-devkit/architect    0.2002.1
@angular-devkit/core         20.2.1
@angular-devkit/schematics   20.2.1
@angular/build               20.2.1
@angular/cli                 20.2.1
@schematics/angular          20.2.1
rxjs                         7.8.2
typescript                   5.9.2
zone.js                      0.15.1

Anything else?

No response