Add a swift-ci image based on rhel/ubi9 (#318)

Author: MaxDesiatov

swift-ci/master/rhel-ubi/9/Dockerfile

@@ -0,0 +1,23 @@
+FROM redhat/ubi9
+
+RUN groupadd -g 42 build-user && \
+    useradd -m -r -u 42 -g build-user build-user
+
+RUN yum install -y  \
+  git               \
+  gcc-c++           \
+  clang             \
+  cmake             \
+  make              \
+  libcurl-devel     \
+  libedit-devel     \
+  libuuid-devel     \
+  libxml2-devel     \
+  ncurses-devel     \
+  python3-devel     \
+  rsync             \
+  sqlite-devel
+
+USER build-user
+
+WORKDIR /home/build-user