- remove the old LGPL license headers from all files in Spack
- add SPDX headers to all files
- core and most packages are (Apache-2.0 OR MIT)
- a very small number of remaining packages are LGPL-2.1-only
* py-networkx: adding older version py-networkx
* py-pypeflow: new package
* falcon: adding new package
pacbio-daligner: adding new package
pacbio-damasker: adding new package
pacbio-dazz-db: adding new package
pacbio-dextractor: adding new package
* py-networkx: modifying version order to be in line with convention
* falcon: tweaking py-networkx dependency to satisfy setuptools
py-pypeflow: adding missing dependency
* pacbio-dextractor: changing hdf5 dependency
* pacbio-daligner: adding gmake build dep
pacbio-damasker: adding gmake build dep
pacbio-dazz-db: adding gmake build dep
pacbio-dextractor: adding gmake build dep
