Replace player-animation-lib with the Saturn emote library

- Every version depends on org.saturnclient:emotes-fabric
  (${emotes_version}+<mc>, bundled). playEmote plays Saturn's emotes
  through it, and sneaking stops your own emote and tells the server.
  Emotes now work on 1.21.6+ too, where player-animation-lib was
  commented out.
- Removed every player-animation-lib and bendy-lib reference: the KoSmX
  repository, the dependencies, the player_anim properties, and the old
  (partly commented out) code in SaturnProviderImpl and KeyInputHandler.
- Build: Loom 1.15 -> 1.17.21 (the emotes jar is built with 1.17 and
  older Loom refuses it), Gradle 9.3 -> 9.8 (needed by Loom 1.17), and
  sourceSets moved out of the dependencies block in the root build.gradle,
  which Gradle 9.8 rejects.
- common: points at the emote-library branch (saturnclientmc/common#5).

Co-Authored-By: Claude Opus 5.5 <[email protected]>

build.gradle

@@ -4,6 +4,7 @@ subprojects {
     repositories {
         maven { url "https://maven.fabricmc.net/" }
         maven { url "https://git.selimaj.dev/api/packages/selimaj-dev/maven" }
+        maven { url "https://git.selimaj.dev/api/packages/saturnclientmc/maven" }
         mavenCentral()
     }
 
@@ -19,12 +20,12 @@ subprojects {
 configure(subprojects.findAll { it.name != "common" }) {
     dependencies {
         implementation project(":common")
+    }
 
-        sourceSets {
-            main {
-                resources {
-                    srcDir project(":common").file("src/main/resources")
-                }
+    sourceSets {
+        main {
+            resources {
+                srcDir project(":common").file("src/main/resources")
             }
         }
     }