perf(cdk/a11y): tree-shake warnings in production (#23967)

(cherry picked from commit 39921f4)

Author: arturovt

src/cdk/a11y/focus-trap/focus-trap.ts

@@ -164,26 +164,28 @@ export class FocusTrap {
    */
   private _getRegionBoundary(bound: 'start' | 'end'): HTMLElement | null {
     // Contains the deprecated version of selector, for temporary backwards comparability.
-    let markers = this._element.querySelectorAll(
+    const markers = this._element.querySelectorAll(
       `[cdk-focus-region-${bound}], ` + `[cdkFocusRegion${bound}], ` + `[cdk-focus-${bound}]`,
     ) as NodeListOf<HTMLElement>;
 
-    for (let i = 0; i < markers.length; i++) {
-      // @breaking-change 8.0.0
-      if (markers[i].hasAttribute(`cdk-focus-${bound}`)) {
-        console.warn(
-          `Found use of deprecated attribute 'cdk-focus-${bound}', ` +
-            `use 'cdkFocusRegion${bound}' instead. The deprecated ` +
-            `attribute will be removed in 8.0.0.`,
-          markers[i],
-        );
-      } else if (markers[i].hasAttribute(`cdk-focus-region-${bound}`)) {
-        console.warn(
-          `Found use of deprecated attribute 'cdk-focus-region-${bound}', ` +
-            `use 'cdkFocusRegion${bound}' instead. The deprecated attribute ` +
-            `will be removed in 8.0.0.`,
-          markers[i],
-        );
+    if (typeof ngDevMode === 'undefined' || ngDevMode) {
+      for (let i = 0; i < markers.length; i++) {
+        // @breaking-change 8.0.0
+        if (markers[i].hasAttribute(`cdk-focus-${bound}`)) {
+          console.warn(
+            `Found use of deprecated attribute 'cdk-focus-${bound}', ` +
+              `use 'cdkFocusRegion${bound}' instead. The deprecated ` +
+              `attribute will be removed in 8.0.0.`,
+            markers[i],
+          );
+        } else if (markers[i].hasAttribute(`cdk-focus-region-${bound}`)) {
+          console.warn(
+            `Found use of deprecated attribute 'cdk-focus-region-${bound}', ` +
+              `use 'cdkFocusRegion${bound}' instead. The deprecated attribute ` +
+              `will be removed in 8.0.0.`,
+            markers[i],
+          );
+        }
       }
     }
 
@@ -207,7 +209,10 @@ export class FocusTrap {
 
     if (redirectToElement) {
       // @breaking-change 8.0.0
-      if (redirectToElement.hasAttribute(`cdk-focus-initial`)) {
+      if (
+        (typeof ngDevMode === 'undefined' || ngDevMode) &&
+        redirectToElement.hasAttribute(`cdk-focus-initial`)
+      ) {
         console.warn(
           `Found use of deprecated attribute 'cdk-focus-initial', ` +
             `use 'cdkFocusInitial' instead. The deprecated attribute ` +