perf(ivy): avoid memory allocation in the isAnimationProp check (#32997)

Accessing a string's character at index allocates a new, single character string.
A better (faster) check is to use `charCodeAt` that doesn't trigger allocation.

This simple change speeds up the element_text_create benchmark by ~7%.

PR Close #32997

packages/core/test/bundling/cyclic_import/bundle.golden_symbols.json

@@ -2,9 +2,6 @@
   {
     "name": "ACTIVE_INDEX"
   },
-  {
-    "name": "ANIMATION_PROP_PREFIX"
-  },
   {
     "name": "BINDING_INDEX"
   },

packages/core/test/bundling/todo/bundle.golden_symbols.json

@@ -2,9 +2,6 @@
   {
     "name": "ACTIVE_INDEX"
   },
-  {
-    "name": "ANIMATION_PROP_PREFIX"
-  },
   {
     "name": "BINDING_INDEX"
   },