fix: drop the unused GIF library that blocks 16 KB page size support (#19)

Play rejects updates whose native libraries are not aligned for 16 KB memory pages,
enforced since Nov 1 2025. Measuring the released bundle showed exactly one library
short, and only on one ABI:

  arm64-v8a   7/7 aligned at 0x4000
  x86_64      6/7 aligned; libpl_droidsonroids_gif.so at 0x1000

That library comes from pl.droidsonroids.gif:android-gif-drawable 1.2.19, inherited
from upstream and never used here: no GifDrawable, GifImageView, GifTextView or
pl.droidsonroids reference exists in any Kotlin, Java or XML file in the project.

Removing it beats upgrading to 1.2.32 — an unused dependency should not be carried at
any version, and this also drops roughly 175 KB of dead native code across four ABIs.

Everything else in the bundle was already aligned, and jniLibs.useLegacyPackaging is
already false, so nothing more is needed for the requirement.

app/build.gradle

@@ -302,7 +302,6 @@ dependencies {
     implementation retrofitDep
     implementation gsonConvertedDep
 
-    implementation gifDep
 
     compileOnly wsDep
 

build.gradle

@@ -53,8 +53,6 @@ buildscript {
 
         substrateSdkVersion = '2.11.0'
 
-        gifVersion = '1.2.19'
-
         zXingVersion = '3.4.0'
         zXingEmbeddedVersion = '3.5.0@aar'
 
@@ -166,8 +164,6 @@ buildscript {
         substrateSdkDep = "io.github.nova-wallet.substrate-sdk-android:core:$substrateSdkVersion"
         substrateSdkSerializationDep = "io.github.nova-wallet.substrate-sdk-android:kotlinx-serialization-scale:$substrateSdkVersion"
 
-        gifDep = "pl.droidsonroids.gif:android-gif-drawable:$gifVersion"
-
         wsDep = "com.neovisionaries:nv-websocket-client:$wsVersion"
 
         shimmerDep = "com.facebook.shimmer:shimmer:$shimmerVersion"