scripts/ci/setup: ninja missing from build-environment

ninja-build is missing from the RHEL environment, so a system prepared
with that script would still fail to compile QEMU.
Tested on a Fedora 36

Signed-off-by: Lucas Mateus Castro (alqotel) <lucas.araujo@eldorado.org.br>
Message-Id: <20220922135516.33627-2-lucas.araujo@eldorado.org.br>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20220929114231.583801-2-alex.bennee@linaro.org>

scripts/ci/setup/build-environment.yml

@@ -153,6 +153,7 @@
           - make
           - mesa-libEGL-devel
           - nettle-devel
+          - ninja-build
           - nmap-ncat
           - perl-Test-Harness
           - pixman-devel