Replace period with hyphens in place, instead of declaring environment variable.

PiperOrigin-RevId: 454618760
Change-Id: Ia6501f62ff3769a591497ac3413dc7526b31d1cc

docker/Dockerfile

@@ -21,11 +21,10 @@ ARG CUDA
 # Use bash to support string substitution.
 SHELL ["/bin/bash", "-c"]
 
-RUN apt-get update && CUDA_HYPHENS=${CUDA//./-} DEBIAN_FRONTEND=noninteractive \
-      apt-get install -y \
+RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y \
         build-essential \
         cmake \
-        cuda-command-line-tools-$(cut -f1,2 -d- <<< ${CUDA_HYPHENS}) \
+        cuda-command-line-tools-$(cut -f1,2 -d- <<< ${CUDA//./-}) \
         git \
         hmmer \
         kalign \