As @krumnack pointed out, with harmonising the builds of all projects in !39481 (merged), I made the builds of AnalysisBase fail (out of the box) on hosts that do not have access to CVMFS. This was because of some unnecessary logic in the LCG_RELEASE_BASE.sh and TDAQ_RELEASE_BASE.sh scripts. Which I now removed.
The build of AnalysisBase does not use the LCG_RELEASE_BASE or TDAQ_RELEASE_BASE environment variables. But it also doesn't hurt it if they are set during its build. This is why I didn't introduce any logic into the common build script for not setting these up for the standalone project.
While at it, I also added another simplification. The build_externals.sh scripts could be made just a little simpler, by not setting one of the variables that they were setting before.
Unlike !39481 (merged), these should be pretty safe updates...
