chore: remove unnecessary test script

- Fix distroless build failure by replacing heredoc syntax with explicit shell call
  - Distroless has no shell, must use /bin/sh from build stage mounts
  - Fixes CI/CD pipeline that has been failing for months (#20414)

- Security updates for base images:
  - Distroless: debian11 → debian12 (addresses CVEs in #22594)
  - Alpine: 3.20 → 3.21 (latest stable)

- Fix incorrect symlink name 'nodebun' → 'node' in distroless

This minimal fix addresses the critical issue preventing distroless images
from being published while maintaining the minimal attack surface philosophy
of distroless containers.

dockerhub/alpine/Dockerfile

@@ -1,4 +1,4 @@
-FROM alpine:3.20 AS build
+FROM alpine:3.21 AS build
 
 # https://github.com/oven-sh/bun/releases
 ARG BUN_VERSION=latest
@@ -44,7 +44,7 @@ RUN apk --no-cache add ca-certificates curl dirmngr gpg gpg-agent unzip \
     && rm -f "bun-linux-$build.zip" SHASUMS256.txt.asc SHASUMS256.txt \
     && chmod +x /usr/local/bin/bun
 
-FROM alpine:3.20
+FROM alpine:3.21
 
 # Disable the runtime transpiler cache by default inside Docker containers.
 # On ephemeral containers, the cache is not useful

dockerhub/distroless/Dockerfile

@@ -55,7 +55,7 @@ RUN apt-get update -qq \
     && which bun \
     && bun --version
 
-FROM gcr.io/distroless/base-nossl-debian11
+FROM gcr.io/distroless/base-nossl-debian12
 
 # Disable the runtime transpiler cache by default inside Docker containers.
 # On ephemeral containers, the cache is not useful
@@ -69,16 +69,17 @@ ENV BUN_INSTALL_BIN=${BUN_INSTALL_BIN}
 COPY --from=build /usr/local/bin/bun /usr/local/bin/
 ENV PATH "${PATH}:/usr/local/bun-node-fallback-bin"
 
-# Temporarily use the `build`-stage image binaries to create a symlink:
+# Temporarily use the `build`-stage image binaries to create symlinks:
+# We must use the shell from the build stage since distroless has no shell
 RUN --mount=type=bind,from=build,source=/usr/bin,target=/usr/bin \
     --mount=type=bind,from=build,source=/bin,target=/bin \
     --mount=type=bind,from=build,source=/usr/lib,target=/usr/lib \
     --mount=type=bind,from=build,source=/lib,target=/lib \
-    <<EOF
-  ln -s /usr/local/bin/bun /usr/local/bin/bunx
-  which bunx
-  mkdir -p /usr/local/bun-node-fallback-bin
-  ln -s /usr/local/bin/bun /usr/local/bun-node-fallback-bin/nodebun
-EOF
+    /bin/sh -c ' \
+      ln -s /usr/local/bin/bun /usr/local/bin/bunx && \
+      which bunx && \
+      mkdir -p /usr/local/bun-node-fallback-bin && \
+      ln -s /usr/local/bin/bun /usr/local/bun-node-fallback-bin/node \
+    '
 
 ENTRYPOINT ["/usr/local/bin/bun"]