chore(rootfs/Dockerfile): update shfmt to 3.0.1 (#213)

See https://github.com/mvdan/sh/releases/tag/v3.0.1

Author: mboersma

rootfs/Dockerfile

@@ -14,7 +14,7 @@ ENV AZCLI_VERSION=2.0.79 \
     GOLANGCI_LINT_VERSION=v1.23.1 \
     PROTOBUF_VERSION=3.7.0 \
     SHELLCHECK_VERSION=v0.7.0 \
-    SHFMT_VERSION=3.0.0 \
+    SHFMT_VERSION=3.0.1 \
     PATH=$PATH:/usr/local/go/bin:/go/bin:/usr/local/bin/docker \
     GOPATH=/go