Switch from GitLab to GitHub

[cameronrutherford]

Before Initial Switch:

• [x] Clean up stale branches / issues (#37)
• [x] Merge any remaining work in MRs
• [x] Issues moved from GitLab to GitHub (also move any stale PRs manually)
• [x] PNNL GitLab push mirror (#7)
• [x] PNNL GPU pipelines posting status (#7)
• [x] Ascent pipelines posting status (#7)

After Initial Switch:

• [x] Tag new release to signify switch, and update spack package with URL + version (Planned 1.6.0)
  • [x] Ensure tags are updated and all branches match
• [x] Update about section and logo in GitHub (@abhyshr took care of this)
• [x] Add Issue / Merge request template (#36)
• [x] Badges updated for pipelines / ExaGO logo update (#15)
  • [x] This includes the new GitHub actions, and pre-commit (maybe codecov one day)
• [x] Crusher pipelines fixed and posting status. (#9)
• [x] GitHub Actions pipelines
  • [x] pre-commit instead of CMake based linting (#5)
  • [x] spack CI builds in GitHub actions for CPU only builds (#11 #15)

Follow up work:

• [x] Quarto Documentation + GitHub wiki integration (#32)
• [x] Crusher CI status posting (#9)
• [x] Add spack module pipelines to Ascent and Crusher (#10 #34)
• [x] Submodules removed in favor of external packages (#38)

[cameronrutherford]

pre-commit documentation is a must

[cameronrutherford]

In addition to MR / Issue template, we should include requirements to manually run and have crusher CI pass before merging. Can't enforce through GitHub, so this is a manual / optional req

[cameronrutherford]

Captured reamining tasks in sub issues