refactor: remove unnecessary bg-color attributes and move to ui lib vars (#18234)

web/src/routes/(user)/people/+page.svelte

@@ -458,7 +458,7 @@
   <dialog
     open
     transition:fly={{ y: innerHeight, duration: 150, easing: quintOut, opacity: 0 }}
-    class="absolute start-0 top-0 z-[9999] h-full w-full bg-immich-bg dark:bg-immich-dark-bg"
+    class="absolute start-0 top-0 z-[9999] h-full w-full bg-light"
     aria-modal="true"
     aria-labelledby="manage-visibility-title"
     use:focusTrap

web/src/routes/(user)/people/[personId]/[[photos=photos]]/[[assetId=id]]/+page.svelte

@@ -487,7 +487,7 @@
 </header>
 
 <main
-  class="relative h-dvh overflow-hidden bg-immich-bg tall:ms-4 md:pt-[var(--navbar-height-md)] pt-[var(--navbar-height)] dark:bg-immich-dark-bg"
+  class="relative h-dvh overflow-hidden tall:ms-4 md:pt-[var(--navbar-height-md)] pt-[var(--navbar-height)]"
   use:scrollMemoryClearer={{
     routeStartsWith: AppRoute.PEOPLE,
     beforeClear: () => {