fix: update cache record TTL to not account for Daylight Saving time (#21389)

lib/util/github/graphql/cache-strategies/package-cache-strategy.ts

@@ -17,7 +17,9 @@ export class GithubGraphqlPackageCacheStrategy<
   ): Promise<void> {
     if (this.hasUpdatedItems) {
       const expiry = this.createdAt.plus({
-        days: AbstractGithubGraphqlCacheStrategy.cacheTTLDays,
+        // Not using 'days' as it does not handle adjustments for Daylight Saving time.
+        // The offset in the resulting DateTime object does not match that of the expiry or this.now.
+        hours: AbstractGithubGraphqlCacheStrategy.cacheTTLDays * 24,
       });
       const ttlMinutes = expiry.diff(this.now, ['minutes']).as('minutes');
       if (ttlMinutes && ttlMinutes > 0) {