Update page footer to add sponsor link

[delucis]

Description (required)

• This PR updates our page footer component to replace the feedback widget with a link to sponsor Astro on OpenCollective.
• It also removes the feedback widget from tutorial pages and deletes that code to reduce maintenance.
• While here, icons have been tweaked as well:
  • The contribute link now has a rocket icon instead of an open book
  • The sponsor link uses a heart icon previously used by the community link
  • The community link uses a “multiple people” icon

Before

After

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Tracked Files

File	Note
src/content/i18n/ar.yml	Localization changed, will be marked as complete.
src/content/i18n/de.yml	Localization changed, will be marked as complete.
src/content/i18n/en.yml	Source changed, localizations will be marked as outdated.
src/content/i18n/es.yml	Localization changed, will be marked as complete.
src/content/i18n/fr.yml	Localization changed, will be marked as complete.
src/content/i18n/hi.yml	Localization changed, will be marked as complete.
src/content/i18n/it.yml	Localization changed, will be marked as complete.
src/content/i18n/ja.yml	Localization changed, will be marked as complete.
src/content/i18n/ko.yml	Localization changed, will be marked as complete.
src/content/i18n/pl.yml	Localization changed, will be marked as complete.
src/content/i18n/pt-BR.yml	Localization changed, will be marked as complete.
src/content/i18n/ru.yml	Localization changed, will be marked as complete.
src/content/i18n/zh-CN.yml	Localization changed, will be marked as complete.
src/content/i18n/zh-TW.yml	Localization changed, will be marked as complete.

Warnings reference

Icon	Description
🔄️	The source for this localization has been updated since the creation of this pull request, make sure all changes in the source have been applied.

[sarah11918]

I think this looks great! We haven't been getting much feedback lately, and much of it has been spam. This cleans up the code and I think better aligns the icons!