Using 'latest' for a few of docker images

[wawrzek]

Using the 'latest' tag in a docker image definition is a dangerous practice, especially if the that can point at unstable images. That's the case for both the 'geth' and the 'prysmctl' images.

The recent problem with prysmctl, related to inclusion of incoming Electra work, was mentioned in #55 or #49, but there are more example of user hitting unstable image (e.g. #41).

One of the recent changes to geth caused the Failed to get EIP-1559 fees issue (ethereum/go-ethereum#29898). I also notice problems similar to ethereum/go-ethereum#29880.

The solution is to lock the version of all images (at least the ones not using the stable tag).

[wawrzek]

Example of a fix: ivy-net#2