appease typescript

Author: Rich-Harris

src/runtime/internal/transitions.ts

@@ -87,7 +87,7 @@ export function create_in_transition(node: Element & ElementCSSInlineStyle, fn:
 			easing = linear,
 			tick = noop,
 			css
-		} = config || null_transition;
+		} = config || (null_transition as TransitionConfig);
 
 		if (css) animation_name = create_rule(node, 0, 1, duration, delay, easing, css, uid++);
 		tick(0, 1);
@@ -166,7 +166,7 @@ export function create_out_transition(node: Element & ElementCSSInlineStyle, fn:
 			easing = linear,
 			tick = noop,
 			css
-		} = config || null_transition;
+		} = config || (null_transition as TransitionConfig);
 
 		if (css) animation_name = create_rule(node, 1, 0, duration, delay, easing, css);
 
@@ -260,7 +260,7 @@ export function create_bidirectional_transition(node: Element & ElementCSSInline
 			easing = linear,
 			tick = noop,
 			css
-		} = config || null_transition;
+		} = config || (null_transition as TransitionConfig);
 
 		const program = {
 			start: now() + delay,