update Compose to v1.4.3

noteworthy changes:

• popups (like context menus and non-native windows) are now acessible: https://github.com/JetBrains/compose-multiplatform-core/pull/439
• drag-and-drop support from external applications: https://github.com/JetBrains/compose-multiplatform-core/pull/391 (might be interesting for image sending)

briar-desktop/src/main/kotlin/org/briarproject/briar/desktop/blog/BlogInput.kt

@@ -40,7 +40,7 @@ import androidx.compose.runtime.saveable.rememberSaveable
 import androidx.compose.ui.Alignment.Companion.Top
 import androidx.compose.ui.ExperimentalComposeUiApi
 import androidx.compose.ui.Modifier
-import androidx.compose.ui.input.pointer.PointerIconDefaults
+import androidx.compose.ui.input.pointer.PointerIcon
 import androidx.compose.ui.input.pointer.pointerHoverIcon
 import androidx.compose.ui.unit.dp
 import org.briarproject.bramble.util.StringUtils.utf8IsTooLong
@@ -131,7 +131,7 @@ fun BlogInput(
                     modifier = Modifier
                         .padding(4.dp)
                         .size(32.dp)
-                        .pointerHoverIcon(PointerIconDefaults.Default),
+                        .pointerHoverIcon(PointerIcon.Default),
                 )
             }
         )