Lock the riscv64 image 20240211 snapshot

Both VF2 and LPi4a vendor images are stuck on libc6 2.36 while
the latest sid images build packages that require libc6 2.38.

Additionally, these vendor images do not have the newer T64
transitional packages for Qt and OpenSSL in their repositories.

Dockerfile.riscv64.sid

@@ -1,10 +1,12 @@
-FROM riscv64/debian:sid
+FROM riscv64/debian:sid-20240211
 
 ENV TARGET=embedded
 ENV DISTRO=sid
 
 COPY scripts/install-base-deps.sh /opt/scripts/
-RUN /bin/bash -c /opt/scripts/install-base-deps.sh && \
+RUN sed -i 's|http://deb.debian.org/debian|http://snapshot.debian.org/archive/debian/20240211T000000Z|g' /etc/apt/sources.list.d/debian.sources && \
+    echo "Acquire::Check-Valid-Until false;" > /etc/apt/apt.conf.d/10-nocheckvalid && \
+    /bin/bash -c /opt/scripts/install-base-deps.sh && \
     apt-get clean -y && \
     rm -rf /var/lib/apt/lists/*