Remove unused Gradle dependencies

Remove dependencies flagged as unused by the Dependency Analysis Gradle Plugin
(`./gradlew buildHealth`) and explicitly declared in module build files.

Removals were skipped when the dependency provides transitively something the
module (or a consumer of an `api` dependency) uses directly, as well as for
runtime-only dependencies (element-call-embedded, sentry-android,
rustls-platform-verifier). Dependencies added by the convention plugin helpers
(composeDependencies, testCommonDependencies) are left untouched.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

app/build.gradle.kts

@@ -280,7 +280,6 @@ dependencies {
     implementation(projects.features.migration.api)
     implementation(projects.appnav)
     implementation(projects.appconfig)
-    implementation(projects.libraries.uiStrings)
     implementation(projects.services.analytics.compose)
 
     if (ModulesConfig.pushProvidersConfig.includeFirebase) {
@@ -298,18 +297,13 @@ dependencies {
     implementation(libs.androidx.splash)
     implementation(libs.androidx.core)
     implementation(libs.androidx.corektx)
-    implementation(libs.androidx.lifecycle.runtime)
     implementation(libs.androidx.lifecycle.process)
     implementation(libs.androidx.activity.compose)
     implementation(libs.androidx.startup)
     implementation(libs.androidx.preference)
-    implementation(libs.coil)
 
     implementation(platform(libs.network.okhttp.bom))
     implementation(libs.network.okhttp.logging)
-    implementation(libs.serialization.json)
-
-    implementation(libs.matrix.emojibase.bindings)
 
     testCommonDependencies(libs)
     testImplementation(projects.libraries.matrix.test)