Fix: Clarify F-Droid flavor excludes Google Services

Updated documentation to reflect that the F-Droid flavor automatically excludes Google Services dependencies [here](33a36c4b54/app/build.gradle (L82))

docs/develop.md

@@ -340,10 +340,6 @@ Then either follow the steps for building with or without Firebase.
 Without Firebase, you may want to still change the default `app_base_url` in [values.xml](https://github.com/binwiederhier/ntfy-android/blob/main/app/src/main/res/values/values.xml)
 if you're self-hosting the server. Then run:
 ```
-# Remove Google dependencies (FCM)
-sed -i -e '/google-services/d' build.gradle
-sed -i -e '/google-services/d' app/build.gradle
-
 # To build an unsigned .apk (app/build/outputs/apk/fdroid/*.apk)
 ./gradlew assembleFdroidRelease
 
@@ -351,6 +347,8 @@ sed -i -e '/google-services/d' app/build.gradle
 ./gradlew bundleFdroidRelease
 ```
 
+The F-Droid flavor automatically excludes Google Services dependencies.
+
 ### Build Play flavor (FCM)
 !!! info
     I do build the ntfy Android app using IntelliJ IDEA (Android Studio), so I don't know if these Gradle commands will