Motivation for this change

Update to latest tor-browser-bundle-bin before the current version's src is removed & it fails to build (tor-browser-bundle-bin's src doesn't get cached in tarballs.nixos.org).

Also, this release includes fixes for these security vulnerabilities:

• CVE-2020-26951: Parsing mismatches could confuse and bypass security sanitizer for chrome privileged code
• CVE-2020-16012: Variable time processing of cross-origin images during drawImage calls
• CVE-2020-26953: Fullscreen could be enabled without displaying the security UI
• CVE-2020-26956: XSS through paste (manual and clipboard API)
• CVE-2020-26958: Requests intercepted through ServiceWorkers lacked MIME type restrictions
• CVE-2020-26959: Use-after-free in WebRequestService
• CVE-2020-26960: Potential use-after-free in uses of nsTArray
• CVE-2020-15999: Heap buffer overflow in freetype
• CVE-2020-26961: DoH did not filter IPv4 mapped IP Addresses
• CVE-2020-26965: Software keyboards may have remembered typed passwords
• CVE-2020-26966: Single-word search queries were also broadcast to local network
• CVE-2020-26968: Memory safety bugs fixed in Firefox 83 and Firefox ESR 78.5

Release notes: https://blog.torproject.org/new-release-tor-browser-1005

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS linux)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs 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/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
  838,565,624 → 838,588,592
• Ensured that relevant documentation is up to date
• Fits CONTRIBUTING.md.

FYI maintainers: @joachifm @doublec @hax404 @KarlJoad @matejc @offlinehacker @scaredmushroom @thoughtpolice