remove OSMesa (#9708)

* remove OSMesa

OSMesa is depricated for quite a while and got removed with Mesa 25.1.0

* remove OSMesa from all buildfiles, readmes, etc…

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Co-authored-by: Noisyfox <timemanager.rick@gmail.com>

linux.d/debian

@@ -15,7 +15,6 @@ REQUIRED_DEV_PACKAGES=(
     libgstreamerd-3-dev
     libgtk-3-dev
     libmspack-dev
-    libosmesa6-dev
     libsecret-1-dev
     libspnav-dev
     libssl-dev

linux.d/fedora

@@ -22,7 +22,6 @@ REQUIRED_DEV_PACKAGES=(
     libtool
     m4
     mesa-libGLU-devel
-    mesa-libOSMesa-devel
     ninja-build
     openssl-devel
     perl-FindBin