anydesk: Update anydesk.tar.gz to 6.4.0

[flathubbot]

🤖 This pull request was automatically generated by flathub-infra/flatpak-external-data-checker. Please open an issue if you have any questions or complaints. 🤖

[flathubbot]

Started test build 162317

[flathubbot]

Build 162317 successful To test this build, install it from the testing repository:

flatpak install --user https://dl.flathub.org/build-repo/145394/com.anydesk.Anydesk.flatpakref

[flathubbot]

Started test build 162373

[flathubbot]

Build 162373 successful To test this build, install it from the testing repository:

flatpak install --user https://dl.flathub.org/build-repo/145450/com.anydesk.Anydesk.flatpakref