Update instructions on building SmiServices

[karacolada]

The section on building the Java projects in the root README of the project is out of date. The mentioned files were removed in March 2022 in commit 6cb8048. Java is only required for running CTP at the moment, i.e. at the extraction stage.

Good places to check for updated steps:

• GitHub Actions for CTP
• bin/ctp

[rkm]

Thanks for checking this. Would you like to contribute a PR to update the instructions?

[karacolada]

Sure! Haven't tested the resources linked above, but once I do, I'll update the docs in a PR.

[rkm]

Just a note that I've extracted the logic from the single ./bin/ctpbuildTestPackage.py script out to multiple scripts in order to support some CI updates. (See #1496)