Finish converting most of the undeprecated api to jspecify

patches/api/Friction-API.patch

@@ -14,11 +14,12 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 +
 +import net.kyori.adventure.util.TriState;
 +import org.bukkit.entity.Entity;
-+import org.jetbrains.annotations.NotNull;
++import org.jspecify.annotations.NullMarked;
 +
 +/**
 + * Represents an {@link Entity} that can experience friction with the air and ground.
 + */
++@NullMarked
 +public interface Frictional {
 +
 +    /**
@@ -29,7 +30,6 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 +     *
 +     * @return the entity's friction state
 +     */
-+    @NotNull
 +    TriState getFrictionState();
 +
 +    /**
@@ -42,7 +42,7 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 +     *
 +     * @param state the new friction state to set for the entity
 +     */
-+    void setFrictionState(@NotNull TriState state);
++    void setFrictionState(TriState state);
 +
 +}
 diff --git a/src/main/java/org/bukkit/entity/Item.java b/src/main/java/org/bukkit/entity/Item.java