fix(modal): allow sheet modals to skip focus trap (#30689)

Issue number: resolves #30684

---------

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issue. -->

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## What is the current behavior?
<!-- Please describe the current behavior that you are modifying. -->
Recently, we [fixed some issues with aria-hidden in
modals](https://github.com/ionic-team/ionic-framework/pull/30563),
unfortunately at this time we neglected modals that opt out of focus
trapping. As a result, a lot of modals that disable focus trapping still
have it happening and it doesn't get cleaned up properly on dismiss.

## What is the new behavior?
<!-- Please describe the behavior or changes that are being added by
this PR. -->
We're now properly checking for and skipping focus traps on modals that
do not want them.

## Does this introduce a breaking change?

- [ ] Yes
- [X] No

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  2. Update the BREAKING.md file with the breaking change.
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## Other information

I created regression tests for Angular in this to prevent this from
happening again. I initially tried to do this with core, but the issue
doesn't seem to reproduce with core.

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screenshots of how the component looks before and after the change. -->

Current dev build:
```
 8.7.5-dev.11758652700.103435a3
```

core/src/components/modal/gestures/sheet.ts

@@ -95,6 +95,12 @@ export const createSheetGesture = (
   const contentAnimation = animation.childAnimations.find((ani) => ani.id === 'contentAnimation');
 
   const enableBackdrop = () => {
+    // Respect explicit opt-out of focus trapping/backdrop interactions
+    // If focusTrap is false or showBackdrop is false, do not enable the backdrop or re-enable focus trap
+    const el = baseEl as HTMLIonModalElement & { focusTrap?: boolean; showBackdrop?: boolean };
+    if (el.focusTrap === false || el.showBackdrop === false) {
+      return;
+    }
     baseEl.style.setProperty('pointer-events', 'auto');
     backdropEl.style.setProperty('pointer-events', 'auto');
 
@@ -235,7 +241,10 @@ export const createSheetGesture = (
      * ion-backdrop and .modal-wrapper always have pointer-events: auto
      * applied, so the modal content can still be interacted with.
      */
-    const shouldEnableBackdrop = currentBreakpoint > backdropBreakpoint;
+    const shouldEnableBackdrop =
+      currentBreakpoint > backdropBreakpoint &&
+      (baseEl as HTMLIonModalElement & { focusTrap?: boolean }).focusTrap !== false &&
+      (baseEl as HTMLIonModalElement & { showBackdrop?: boolean }).showBackdrop !== false;
     if (shouldEnableBackdrop) {
       enableBackdrop();
     } else {
@@ -582,7 +591,10 @@ export const createSheetGesture = (
                    * Backdrop should become enabled
                    * after the backdropBreakpoint value
                    */
-                  const shouldEnableBackdrop = currentBreakpoint > backdropBreakpoint;
+                  const shouldEnableBackdrop =
+                    currentBreakpoint > backdropBreakpoint &&
+                    (baseEl as HTMLIonModalElement & { focusTrap?: boolean }).focusTrap !== false &&
+                    (baseEl as HTMLIonModalElement & { showBackdrop?: boolean }).showBackdrop !== false;
                   if (shouldEnableBackdrop) {
                     enableBackdrop();
                   } else {