net/freerdp: update to 2.8.1 release (+)

Notewhorth changes:

• Fixed CVE-2022-39282
• Fixed CVE-2022-39283
• Added missing commit for backported #8041: Remove ALAW/ULAW codecs from linux backends (unreliable)
• Added hash checks for android build script dependencies

Fixed issues:

• Backported #8190: Fix build break with newer FFMPEG versions
• Backported #8234: Updated flatpak with build script
• Backported #8210: Better execinfo support check for android
• Backported #7708: Header now defines DumpThreadHandles
• Backported #8176: Check fullscreen state and not setting
• Backported #8236: Send resize on window state change
• Backported #7611: Audin macOS monterey fix
• Backported #8291: Android build script update

Changelog: https://github.com/FreeRDP/FreeRDP/blob/2.8.1/ChangeLog
Release notes: https://github.com/FreeRDP/FreeRDP/releases/tag/2.8.1

PR: 267034
Submitted by: maintainer
MFH: 2022Q4

(cherry picked from commit c35733e72db722d42788a2ff7ae96c26e1079d4e)