ci: Always install glslangValidator for build jobs

Signed-off-by: Konstantin Seurer <konstantin.seurer@gmail.com>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/15648>

.gitlab-ci/container/debian/arm_build.sh

@@ -22,6 +22,7 @@ apt-get -y install \
 	flex \
 	g++ \
 	git \
+	glslang-tools \
 	kmod \
 	libasan6 \
 	libdrm-dev \

.gitlab-ci/container/fedora/x86_build.sh

@@ -25,6 +25,7 @@ dnf install -y --setopt=install_weak_deps=False \
     gcc \
     gcc-c++ \
     gettext \
+    glslang \
     kernel-headers \
     llvm-devel \
     clang-devel \