meson: Drop gcc 8 support

The libcamera CI has retired gcc 8 testing with the end of life of
Debian Buster at the end of June 2024. As gcc 8 isn't tested anymore, we
can't guarantee it will keep building libcamera correctly. Drop its
support. If anyone still has a compelling use case for gcc 8 support for
libcamera, we will investigate how to restore it in CI.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Umang Jain <umang.jain@ideasonboard.com>
Acked-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

meson.build

@@ -146,16 +146,8 @@ if cc.get_id() == 'clang'
 endif
 
 if cc.get_id() == 'gcc'
-    if cc.version().version_compare('<8')
-        error('gcc version is too old, libcamera requires 8.0 or newer')
-    endif
-
-    # On gcc 8, the file system library is provided in a separate static
-    # library.
     if cc.version().version_compare('<9')
-        cpp_arguments += [
-            '-lstdc++fs',
-        ]
+        error('gcc version is too old, libcamera requires 9.0 or newer')
     endif
 
     # gcc 13 implements the C++23 version of automatic move from local