Add return type annotation to safeValue function for consistency

Co-authored-by: ajnart <49837342+ajnart@users.noreply.github.com>

packages/docker/src/shared.ts

@@ -29,4 +29,4 @@ export const cpuUsageColor = (number: number, state: string): MantineColor => {
   return "red";
 };
 
-export const safeValue = (value?: number, fallback = 0) => (value !== undefined && !isNaN(value) ? value : fallback);
+export const safeValue = (value?: number, fallback = 0): number => (value !== undefined && !isNaN(value) ? value : fallback);