Drop unused dependencies

[jbeich]

From FreeBSD build log using Meson (adds -Wl,--as-needed by default):

=>> Checking shared library dependencies
 0x0000000000000001 NEEDED               Shared library: [libc++.so.1]
 0x0000000000000001 NEEDED               Shared library: [libc.so.7]
 0x0000000000000001 NEEDED               Shared library: [libcxxrt.so.1]
 0x0000000000000001 NEEDED               Shared library: [libdrm.so.2]
 0x0000000000000001 NEEDED               Shared library: [libgbm.so.1]
 0x0000000000000001 NEEDED               Shared library: [libpipewire-0.3.so.0]
 0x0000000000000001 NEEDED               Shared library: [libsdbus-c++.so.1]
 0x0000000000000001 NEEDED               Shared library: [libwayland-client.so.0]