chore(android): remove V10 compat layer

Remove the mapbox-v11-compat/v10 directory and associated build.gradle
conditionals. V10 support was already dropped in 10.3.0; this cleanup
removes the remaining V10 compatibility code to simplify the codebase
for V11-only support going forward.

Author: claude

android/build.gradle

@@ -79,18 +79,7 @@ android {
         sourceSets {
             main {
                 java.srcDirs = ['src/main/java']
-                def mapboxVersion = safeExtGet("RNMapboxMapsVersion", defaultMapboxMapsVersion)
-                def majorMapboxVersion = mapboxVersion.split("\\.")[0] as Integer
-                if (majorMapboxVersion >= 11) {
-                    java.srcDirs += 'src/main/mapbox-v11-compat/v11'
-                } else {
-                    def msg = """
-❌ ERROR: Mapbox v10 is no longer supported as of @rnmapbox/maps 10.3.0
-Please upgrade to Mapbox v11.x or use @rnmapbox/maps 10.2.x
-"""
-                    logger.error(msg)
-                    throw new GradleException(msg)
-                }
+                java.srcDirs += 'src/main/mapbox-v11-compat/v11'
                 java.srcDirs += 'src/main/rn-compat/rn75'
 
                 // Adapted from react-native-screens for consistency
@@ -219,9 +208,6 @@ Please upgrade to Mapbox v11.x or use @rnmapbox/maps 10.2.x
                     }
                 }
 
-                if (safeExtGet("RNMapboxMapsUseV11", false)) {
-                    logger.warn("RNMapboxMapsUseV11 is deprecated, just set RNMapboxMapsVersion to 11.*")
-                }
             }
         }