deployed ecjsrc.jar has fewer files than in 4.26

If you look at ecjsrc-4.26.jar (see [here](https://download.eclipse.org/eclipse/downloads/drops4/R-4.26-202211231800/#JDTCORE)) you'll see three files at the root of the archive, which no longer exist after #181:
* build.xml
* ecj.1
* javax18api.jar

I seem to recall that the first two files were consumed, e.g., by Debian.

I don't know about the latter.

To be honest, I found these files missing also in older releases, so perhaps some scripts got broken even before #181?