remove unnecessary packages from docker files

[gdams]

closes: #458

Confirmed that zlib is no longer required as we bundle it:

docker run -it --name  test-container test-image /bin/bash
6b5acded951e:/# java -version
openjdk version "21.0.1" 2023-10-17 LTS
OpenJDK Runtime Environment Temurin-21.0.1+12 (build 21.0.1+12-LTS)
OpenJDK 64-Bit Server VM Temurin-21.0.1+12 (build 21.0.1+12-LTS, mixed mode, sharing)
6b5acded951e:/# apk del apk-tools -s
WARNING: opening from cache https://dl-cdn.alpinelinux.org/alpine/v3.18/main: No such file or directory
WARNING: opening from cache https://dl-cdn.alpinelinux.org/alpine/v3.18/community: No such file or directory
(1/4) Purging apk-tools (2.14.0-r2)
(2/4) Purging ca-certificates-bundle (20230506-r0)
(3/4) Purging ssl_client (1.36.1-r2)
(4/4) Purging libssl3 (3.1.3-r0)
OK: 47 MiB in 43 packages
6b5acded951e:/# java -version
openjdk version "21.0.1" 2023-10-17 LTS
OpenJDK Runtime Environment Temurin-21.0.1+12 (build 21.0.1+12-LTS)
OpenJDK 64-Bit Server VM Temurin-21.0.1+12 (build 21.0.1+12-LTS, mixed mode, sharing)

Also converted the alpine entrypoint.sh to not require bash

[sxa]

A couple of questions and a suggestion on the comment about the bash->sh change.

[gdams]

@sxa updated ptal

[sxa]

LGTM now - thanks.

[tellison]

This was discussed at the PMC meeting on November 8th and minuted.