Omit type attribute when types key is empty string

### Link to the code that reproduces this issue https://github.com/alan-ws/type-attribute-not-omitted-when-types-key-is-empty-string ### To Reproduce 1. clone repo 2. start app in local 3. open chrome dev tools 4. review elements in head 5. note that <link> tag with rel="alternate" has an empty type ### Current vs. Expected behavior CURRENT: <link> tag with rel="alternate" has an empty type EXPECTED: <link> tag with rel="alternate" contains all props but the empty type is omitted ### Provide environment information ```bash Operating System: Platform: darwin Arch: arm64 Version: Darwin Kernel Version 24.6.0: Mon Jul 14 11:30:29 PDT 2025; root:xnu-11417.140.69~1/RELEASE_ARM64_T6000 Binaries: Node: 23.10.0 npm: 10.9.2 Yarn: N/A pnpm: 9.11.0 Relevant Packages: next: 13.5.4 eslint-config-next: N/A react: 18.2.0 react-dom: 18.2.0 typescript: 4.9.5 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), Vercel (Deployed) ### Additional context _No response_