[PPR] Dynamic route segment params are double encoded

### Link to the code that reproduces this issue https://github.com/marmalade-labs/ppr-double-encode ### To Reproduce 1. Navigate to https://ppr-double-encode.vercel.app/hello%20world (note: this bug _only_ shows when deployed to Vercel, not when running locally). ### Current vs. Expected behavior I expected `hello%20world` to be displayed but instead we see `hello%2520world`. When running locally or with PPR disabled, it works as expected. ### Provide environment information ```bash Operating System: Platform: linux Arch: x64 Version: #1 SMP PREEMPT_DYNAMIC Fri, 04 Oct 2024 21:51:11 +0000 Available memory (MB): 62093 Available CPU cores: 16 Binaries: Node: 22.9.0 npm: 10.8.3 Yarn: 1.22.22 pnpm: 9.12.1 Relevant Packages: next: 15.0.0-canary.181 // Latest available version is detected (15.0.0-canary.181). eslint-config-next: N/A react: 19.0.0-rc-2d16326d-20240930 react-dom: 19.0.0-rc-2d16326d-20240930 typescript: 5.3.3 Next.js Config: output: N/A ``` ### Which area(s) are affected? (Select all that apply) Partial Prerendering (PPR) ### Which stage(s) are affected? (Select all that apply) Vercel (Deployed) ### Additional context @wyattjoh, @ztanner - thought you might find this one interesting !