Dropped unsupported alpine 3.18 and soon unsupported alpine 3.19, add…

[alaendle]

…ed alpine 3.21 and 3.22. Also dropped unsupported node 18 and added node 22. No other changes.

[alaendle]

Ultimately, I'm very interested in getting an up-to-date image on the Docker registry (https://hub.docker.com/_/mongo-express). But instead of an issue, I wanted to create a PR right away; maybe that will shorten the wait. Please let me know if there's anything else I can do to contribute to this goal.

[rtritto]

@alaendle thanks for the PR!

Please can you update?

mongo-express-docker/README.md

Line 32 in 0752343

In below commands go to the folder (e.g. `cd 1.0/20-alpine3.18`) or replace final `.` with folder path (e.g. `1.0/20-alpine3.18`).

- 1.0/20-alpine3.18
+ 1.0/20-alpine3.20

---

For the Docker Image version, I think you can help/contribute, I created #133

[rtritto]

LGTM
Before merge this PR, we need to update the Node version in mongo-express