Revert inclusion of getPageList

v0.14.6 didn't fully remove calls to fetchPageList yet.

library/src/main/java/eu/kanade/tachiyomi/source/Source.kt

@@ -43,11 +43,10 @@ interface Source {
      * Get the list of pages a chapter has. Pages should be returned
      * in the expected order; the index is ignored.
      *
-     * @since extensions-lib 1.4
      * @param chapter the chapter.
      * @return the pages for the chapter.
      */
-    suspend fun getPageList(chapter: SChapter): List<Page> = throw Exception("Stub!")
+    fun fetchPageList(chapter: SChapter): Observable<List<Page>>
 
     @Deprecated(
         "Use the non-RxJava API instead",
@@ -60,10 +59,4 @@ interface Source {
         ReplaceWith("getChapterList"),
     )
     fun fetchChapterList(manga: SManga): Observable<List<SChapter>> = throw Exception("Stub!")
-
-    @Deprecated(
-        "Use the non-RxJava API instead",
-        ReplaceWith("getPageList"),
-    )
-    fun fetchPageList(chapter: SChapter): Observable<List<Page>> = throw Exception("Stub!")
 }