fix: remove duplicate SignerProvider binding from WalletFeatureDependencies

The merge silently combined two independent additions of the same
dependency (my fun signerProvider() and Tron's val signerProvider) since
they landed on non-conflicting lines - Dagger correctly caught this as
[Dagger/DuplicateBindings]. Keeping Tron's val form, since it was already
CI-verified on that branch.

feature-wallet-impl/src/main/java/io/novafoundation/nova/feature_wallet_impl/di/WalletFeatureDependencies.kt

@@ -131,8 +131,6 @@ interface WalletFeatureDependencies {
 
     fun accountRepository(): AccountRepository
 
-    fun signerProvider(): SignerProvider
-
     fun assetsDao(): AssetDao
 
     fun tokenDao(): TokenDao