Update website footer link to new LF Projects Series LLC trademark disclaimer

[thisisobate]

I noticed the link to the trademark disclaimer references the old LF trademark disclaimer page. We need to update it to the new Series of LF Projects, LLC website.

Link should Reference https://lfprojects.org/policies/

[kubeboiii]

Opened PR #378 for this.

The footer "Trademark Usage" link in src/components/footer.tsx now points to https://lfprojects.org/policies/ instead of https://www.linuxfoundation.org/trademark-usage/. Link label, target="_blank", and rel="noopener noreferrer" are unchanged.

Verified locally with npm run dev by clicking the footer link on the homepage.