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>

features/joinroom/impl/build.gradle.kts

@@ -37,12 +37,9 @@ dependencies {
     implementation(projects.features.invite.api)
     implementation(projects.features.roomdirectory.api)
     implementation(projects.services.analytics.api)
-    implementation(projects.libraries.preferences.api)
-    implementation(projects.appconfig)
 
     testCommonDependencies(libs, true)
     testImplementation(projects.features.invite.test)
     testImplementation(projects.libraries.matrix.test)
-    testImplementation(projects.libraries.preferences.test)
     testImplementation(projects.libraries.previewutils)
 }