streamlink: patch tests for compatibility with Requests 2.26

[DeeUnderscore]

Motivation for this change

Fails to build currently: https://hydra.nixos.org/build/153000251

Applying upstream patch from streamlink/streamlink#4022

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandbox = true set in nix.conf? (See Nix manual)
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all packages that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• 21.11 Release Notes (or backporting 21.05 Release notes)
  • (Package updates) Added a release notes entry if the change is major or breaking
  • (Module updates) Added a release notes entry if the change is significant
  • (Module addition) Added a release notes entry if adding a new NixOS module
• Fits CONTRIBUTING.md.

[r-rmcgibbo]

Result of nixpkgs-review pr 138201 at 299d4d7 run on x86_64-linux 1

2 packages built successfully:

• streamlink
• streamlink-twitch-gui-bin

[bobby285271]

Result of nixpkgs-review pr 138201 run on x86_64-linux 1

2 packages built:

• streamlink
• streamlink-twitch-gui-bin