re-add dynamic feature flags for isInputPending (#27919)

## Summary

these were removed in #26617. adds
them back so we can conduct another experiment.

## How did you test this change?
`yarn test-www`

DiffTrain build for commit c81f4e0.

Author: noahlemen

compiled-rn/facebook-fbsource/xplat/js/RKJSModules/vendor/react-test-renderer/cjs/ReactTestRenderer-dev.js

@@ -25524,7 +25524,7 @@ if (__DEV__) {
       return root;
     }
 
-    var ReactVersion = "18.3.0-canary-9723093df-20240109";
+    var ReactVersion = "18.3.0-canary-c81f4e02b-20240109";
 
     // Might add PROFILE later.
 

compiled-rn/facebook-fbsource/xplat/js/RKJSModules/vendor/react-test-renderer/cjs/ReactTestRenderer-prod.js

@@ -9117,7 +9117,7 @@ var devToolsConfig$jscomp$inline_1037 = {
     throw Error("TestRenderer does not support findFiberByHostInstance()");
   },
   bundleType: 0,
-  version: "18.3.0-canary-9723093df-20240109",
+  version: "18.3.0-canary-c81f4e02b-20240109",
   rendererPackageName: "react-test-renderer"
 };
 var internals$jscomp$inline_1230 = {
@@ -9148,7 +9148,7 @@ var internals$jscomp$inline_1230 = {
   scheduleRoot: null,
   setRefreshHandler: null,
   getCurrentFiber: null,
-  reconcilerVersion: "18.3.0-canary-9723093df-20240109"
+  reconcilerVersion: "18.3.0-canary-c81f4e02b-20240109"
 };
 if ("undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__) {
   var hook$jscomp$inline_1231 = __REACT_DEVTOOLS_GLOBAL_HOOK__;

compiled-rn/facebook-fbsource/xplat/js/RKJSModules/vendor/react-test-renderer/cjs/ReactTestRenderer-profiling.js

@@ -9545,7 +9545,7 @@ var devToolsConfig$jscomp$inline_1079 = {
     throw Error("TestRenderer does not support findFiberByHostInstance()");
   },
   bundleType: 0,
-  version: "18.3.0-canary-9723093df-20240109",
+  version: "18.3.0-canary-c81f4e02b-20240109",
   rendererPackageName: "react-test-renderer"
 };
 var internals$jscomp$inline_1271 = {
@@ -9576,7 +9576,7 @@ var internals$jscomp$inline_1271 = {
   scheduleRoot: null,
   setRefreshHandler: null,
   getCurrentFiber: null,
-  reconcilerVersion: "18.3.0-canary-9723093df-20240109"
+  reconcilerVersion: "18.3.0-canary-c81f4e02b-20240109"
 };
 if ("undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__) {
   var hook$jscomp$inline_1272 = __REACT_DEVTOOLS_GLOBAL_HOOK__;

compiled-rn/facebook-fbsource/xplat/js/RKJSModules/vendor/react/cjs/React-dev.js

@@ -24,7 +24,7 @@ if (__DEV__) {
     ) {
       __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStart(new Error());
     }
-    var ReactVersion = "18.3.0-canary-9723093df-20240109";
+    var ReactVersion = "18.3.0-canary-c81f4e02b-20240109";
 
     // ATTENTION
     // When adding new symbols to this file,

compiled-rn/facebook-fbsource/xplat/js/RKJSModules/vendor/react/cjs/React-prod.js

@@ -580,4 +580,4 @@ exports.useSyncExternalStore = function (
 exports.useTransition = function () {
   return ReactCurrentDispatcher.current.useTransition();
 };
-exports.version = "18.3.0-canary-9723093df-20240109";
+exports.version = "18.3.0-canary-c81f4e02b-20240109";

compiled-rn/facebook-fbsource/xplat/js/RKJSModules/vendor/react/cjs/React-profiling.js

@@ -576,7 +576,7 @@ exports.useSyncExternalStore = function (
 exports.useTransition = function () {
   return ReactCurrentDispatcher.current.useTransition();
 };
-exports.version = "18.3.0-canary-9723093df-20240109";
+exports.version = "18.3.0-canary-c81f4e02b-20240109";
 "undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__ &&
   "function" ===
     typeof __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStop &&

compiled-rn/facebook-fbsource/xplat/js/react-native-github/Libraries/Renderer/REVISION

@@ -1 +1 @@
-9723093df319f06886fe488d6d88ff615a3e8fc3
+c81f4e02bab9d03e1583047d041fdb5e4eb19415