magpie4 >= 2.3.10, adjust export to MAgPIE 4.8, lock while running gamscompile test

[orichters]

Purpose of this PR

• most recent MAgPIE version should be run with magpie4 2.3.10, which is backwards compatible
• https://mattermost.pik-potsdam.de/rd3/pl/3hrwa7dmh3yh3br5x61bhif5hh
• adjust model name for the NGFS export
• lock model while running gamscompile in test mode to avoid that it runs while some other run is deleting input files

Type of change

• [x] Avoid using wrong R package version

Checklist:

• [x] My code follows the coding etiquette
• [x] I performed a self-review of my own code
• [x] I explained my changes within the PR, particularly in hard-to-understand areas
• [x] I checked that the in-code documentation is up-to-date
• [x] All automated model tests pass ([ FAIL 0 | WARN 0 | SKIP 6 | PASS 81 ] in the output of make test)