Add decentralized-internet package (#15129)

* Create package.py

* Update package.py

* Update package.py

* Update package.py

* Update package.py

* Update var/spack/repos/builtin/packages/decentralized-internet/package.py

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Co-Authored-By: Adam J. Stewart <ajstewart426@gmail.com>

* Update package.py

Co-authored-by: Adam J. Stewart <ajstewart426@gmail.com>