build: Post-release version bump to 2.99.3
build: Post-release version bump to 2.99.3

openmedicus/gtk-sharp,antoniusriha/gtk-sharp,antoniusriha/gtk-sharp,openmedicus/gtk-sharp,Gankov/gtk-sharp,orion75/gtk-sharp,akrisiun/gtk-sharp,akrisiun/gtk-sharp,Gankov/gtk-sharp,sillsdev/gtk-sharp,orion75/gtk-sharp,Gankov/gtk-sharp,openmedicus/gtk-sharp,openmedicus/gtk-sharp,sillsdev/gtk-sharp,openmedicus/gtk-sharp,akrisiun/gtk-sharp,antoniusriha/gtk-sharp,openmedicus/gtk-sharp,sillsdev/gtk-sharp,openmedicus/gtk-sharp,akrisiun/gtk-sharp,akrisiun/gtk-sharp,orion75/gtk-sharp,sillsdev/gtk-sharp,sillsdev/gtk-sharp,orion75/gtk-sharp,antoniusriha/gtk-sharp,orion75/gtk-sharp,Gankov/gtk-sharp,antoniusriha/gtk-sharp,Gankov/gtk-sharp,Gankov/gtk-sharp