Release 1.4.2

[shuds13]

Target date: ASAP

• Fix under-utilized resource usage. Fix zero GPU case when GPUs assigned to worker #1398
• Fixes bug causing executor to wrongly increase processor counts when not all nodes are utilized.
• Fixes case where setting num_gpus to zero was treated as None.
• Add proxystore example. Proxystore  #1326
• Add missing PerlmutterGPU specs. Add missing PerlmutterGPU specs #1393
• Handle case where Perlmutter detected but no partition. Feature/detect perlmutter login nodes #1391
• Launch environment scripts in shell. Feature/libe env script shell #1392

[jlnav]

Done!