Drop Python 3.8, add CUDA 12.1.1, update some versions. (#53)

This PR drops images for Python 3.8 and adds images with CUDA 12.1.1.
While CUDA 12.1 is not yet planned for our CI matrix, it would be useful
to have these images for local testing.

Dockerfile

@@ -1,6 +1,6 @@
-ARG CUDA_VER=11.5.1
-ARG LINUX_VER=ubuntu20.04
-ARG PYTHON_VER=3.8
+ARG CUDA_VER=11.8.0
+ARG LINUX_VER=ubuntu22.04
+ARG PYTHON_VER=3.10
 FROM rapidsai/mambaforge-cuda:cuda${CUDA_VER}-base-${LINUX_VER}-py${PYTHON_VER}
 
 ARG TARGETPLATFORM
@@ -81,7 +81,7 @@ RUN rapids-mamba-retry install -y \
     gh \
     git \
     jq \
-    "sccache>=0.3.2" \
+    "sccache==0.4.2" \
   && conda clean -aipty
 
 # Install codecov binary

axis.yaml

@@ -4,8 +4,8 @@ CUDA_VER:
   - "11.5.1"
   - "11.8.0"
   - "12.0.1"
+  - "12.1.1"
 PYTHON_VER:
-  - "3.8"
   - "3.9"
   - "3.10"
 LINUX_VER: