make static image import output path consistent with other media (#30168)
This will ensure an image hashed consistently regardless of how its imported:
- `import file from "./file.png"` -> /_next/static/media/file.12345678.png
- `url(./file.png)` -> /_next/static/media/file.12345678.png
- `new URL("./file.png", import.meta.url)` -> /_next/static/media/file.12345678.png