Cannot add dynamic application/json+oembed using app router

[Prushka]

Link to the code that reproduces this issue

https://github.com/Prushka/photosite

To Reproduce

NextJS 13+ app router: There's no option to add a header in this format using generateMetadata:
<link type="application/json+oembed" href="https://....json" />

See: https://oembed.com/

Current vs. Expected behavior

I expect to be able to add oEmbed Json as a metadata or header inside a page or layout.
The component only seems to work in pages route.

Provide environment information

Operating System:
  Platform: darwin
  Arch: arm64
  Version: Darwin Kernel Version 24.1.0: Fri Aug 16 19:18:40 PDT 2024; root:xnu-11215.40.42~4/RELEASE_ARM64_T6020
  Available memory (MB): 65536
  Available CPU cores: 12
Binaries:
  Node: 22.8.0
  npm: 10.8.2
  Yarn: 1.22.19
  pnpm: 8.15.4
Relevant Packages:
  next: 14.2.10 // Latest available version is detected (14.2.10).
  eslint-config-next: 14.2.5
  react: 18.3.1
  react-dom: 18.3.1
  typescript: 5.6.2
Next.js Config:
  output: N/A

Which area(s) are affected? (Select all that apply)

Metadata

Which stage(s) are affected? (Select all that apply)

next dev (local), next build (local)

Additional context

No response