Update dependency io.reactivex.rxjava3:rxjava to v3.1.8 (#182)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

gradle/libs.versions.toml

@@ -140,7 +140,7 @@ androidx-room-rxjava3 = { module = 'androidx.room:room-rxjava3', version.ref = '
 
 # RxJava
 rxandroid = 'io.reactivex.rxjava3:rxandroid:3.0.0'
-rxjava = 'io.reactivex.rxjava3:rxjava:3.0.7'
+rxjava = 'io.reactivex.rxjava3:rxjava:3.1.8'
 
 # WorkManager
 androidx-work-runtime-ktx = { module = 'androidx.work:work-runtime-ktx', version.ref = 'work' }