chore(#376): upgrade build JDK from 17 to 21 (#377)

Co-authored-by: M57 <hy4ri@users.noreply.github.com>

app/build.gradle.kts

@@ -75,8 +75,8 @@ android {
         }
     }
     compileOptions {
-        sourceCompatibility = JavaVersion.VERSION_17
-        targetCompatibility = JavaVersion.VERSION_17
+        sourceCompatibility = JavaVersion.VERSION_21
+        targetCompatibility = JavaVersion.VERSION_21
     }
     buildFeatures {
         compose = true
@@ -99,7 +99,7 @@ android {
 }
 
 kotlin {
-    jvmToolchain(17)
+    jvmToolchain(21)
 }
 
 room {