Update anchors for storage/transfer faqs

Step 1: What is changing in this MR?

Anchors for the FAQ point on when storage/transfer limits go into effect under Storage and Transfer Limits > When are the future GitLab SaaS namespace storage and transfer limits applicable? have been updated recently it looks like, but the Pricing table still pointed at the old URL anchors under Premium and Ultimate for footnote references [1], [2], [3], and [4].

Additionally, the Free tier footnotes [1] and [2] maybe should be updated to point at the same anchor, but since they currently point at an entirely unrelated FAQ point, which I wasn't sure if that's intentional or not, I didn't change them here.

Step 2: Ensure that your changes comply with the following, where applicable:

• I, the Assignee, have run Axe tools on any updated pages, and fixed the relevant accessibility issues.
• These changes meet a specific OKR or item in our Quarterly Plan.
• These changes work on both Safari, Chrome, and Firefox.
• These changes have been reviewed for Visual Quality Assurance and Functional Quality Assurance on Mobile, Desktop, and Tablet.
• These changes work with our Google Analytics and SEO tools.
• These changes have been documented as expected.