chore(deps): pin alpine docker tag to 4bcff63 (#5)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

Dockerfile

@@ -1,5 +1,5 @@
 # Stage 1: Download and extract ocm binary
-FROM alpine AS downloader
+FROM alpine@sha256:4bcff63911fcb4448bd4fdacec207030997caf25e9bea4045fa6c8c44de311d1 AS downloader
 ARG TARGETOS
 ARG TARGETARCH
 RUN apk add --no-cache curl tar