configure.ac: Don't check LLVM version in require_llvm

configure.ac: Don't check LLVM version in require_llvm

This is actually not needed because the version is checked later.

Around line 2380
if test "x$enable_gallium_llvm" == "xyes"; then
    llvm_check_version_for $LLVM_REQUIRED_GALLIUM "gallium"
    llvm_add_default_components "gallium"
fi

Cc: "17.0" <mesa-stable@lists.freedesktop.org>
Cc: Tobias Droste <tdroste@gmx.de>
Signed-off-by: Tobias Droste <tdroste@gmx.de>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com> (v1)
v2: [Emil Velikov: rebase/respin series order]
Signed-off-by: Emil Velikov <emil.velikov@collabora.com>