util/docker: Change Debian suite from Sid to stable

Debian sid is too unstable at this point, and frequently ends up having
issues that cause the coreboot-sdk docker image to fail to build. Using
stable also better reflects what users will typically be running.

Also remove the parameters to quiet the apt-get install command so that
if something does break, we can see what happened more easily.

Fixes bug 536

Signed-off-by: Martin Roth <gaumless@gmail.com>
Change-Id: I41b6464b024df89c114db2cdb9367c0526eb0297
Reviewed-on: https://review.coreboot.org/c/coreboot/+/82411
Reviewed-by: Matt DeVillier <matt.devillier@gmail.com>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Felix Singer <service+coreboot-gerrit@felixsinger.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

util/docker/coreboot-sdk/Dockerfile

@@ -2,7 +2,7 @@
 #
 #   make coreboot-sdk
 
-FROM debian:sid AS coreboot-sdk
+FROM debian:stable AS coreboot-sdk
 
 # The coreboot Commit-ID to build the toolchain from.
 ARG DOCKER_COMMIT
@@ -14,7 +14,7 @@ ARG CROSSGCC_PARAM
 RUN \
 	useradd -p locked -m coreboot && \
 	apt-get -qq update && \
-	apt-get -qqy install --no-install-recommends \
+	apt-get -y install --no-install-recommends \
 		bash-completion \
 		bc \
 		bison \
@@ -34,7 +34,7 @@ RUN \
 		gawk \
 		gcc \
 		git \
-		gnat-13 \
+		gnat \
 		golang \
 		graphicsmagick-imagemagick-compat \
 		graphviz \