fix(performance): updating nuxt-image implementation

Step 1: What is changing in this MR?

We would like to complete a 1st iteration in FY25 to improve INP and LCP scores for pages built by the buyer experience repository by updating our current nuxt-img tags by

1. lowering our image quality to (90-99%)
2. converting images formats to webp

related to #3576 (closed)

Production	Review app
https://about.gitlab.com/	https://update-nuxt-image.about.gitlab-review.app/
https://about.gitlab.com/company	https://update-nuxt-image.about.gitlab-review.app/company
https://about.gitlab.com/customers	https://update-nuxt-image.about.gitlab-review.app/customers
https://about.gitlab.com/dedicated	https://update-nuxt-image.about.gitlab-review.app/dedicated
https://about.gitlab.com/get-started	https://update-nuxt-image.about.gitlab-review.app/get-started/
https://about.gitlab.com/solutions/code-suggestions	https://update-nuxt-image.about.gitlab-review.app/solutions/code-suggestions/
https://about.gitlab.com/pricing	https://update-nuxt-image.about.gitlab-review.app/pricing/
https://about.gitlab.com/support	https://update-nuxt-image.about.gitlab-review.app/support/
https://about.gitlab.com/gitlab-duo	https://update-nuxt-image.about.gitlab-review.app/gitlab-duo/

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 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.

Build Variables:

• Use Contentful Preview API