fix(cli): iOS app signature not retaining entitlements, closes #11089 (#11184)

* fix(cli): iOS app signature not retaining entitlements, closes #11089

The IPA does not retain the entitlements as a regression from #10854 which removed the signing step from the build() and archive(), deferring to the export() call

To retain the entitlements we need to force sign one of the files in the app bundle. The most reliable way to do this is to use a self signed certificate as a dummy signature - it is replaced by the export() call so we do not rely on any user provided certificate

Additionally the export options are incorrectly configuring a manual signing, preventing Xcode from properly managing provisioning profiles, which is also part of the fix

* fix header

Author: lucasfernog

.changes/fix-ios-app-export.md

@@ -0,0 +1,6 @@
+---
+"tauri-cli": patch:bug
+"@tauri-apps/cli": patch:bug
+---
+
+Fix iOS application not including the provided capabilities (entitlements).

.changes/self-signed-cert.md

@@ -0,0 +1,5 @@
+---
+"tauri-macos-sign": patch:enhance
+---
+
+Added `Keychain::with_certificate_file` and `certificate::generate_self_signed`.