CI updates for release

[lisanna-dettwyler]

Tracking CI updates from https://github.com/GaloisInc/saw-script/tree/release-0.8

Closes #1171

• Publish docker images -> ghcr.io:
  

  saw-script/.github/workflows/ci.yml

  Lines 283 to 288 in 245ff82

  	- file: saw/Dockerfile
  	image: ghcr.io/galoisinc/saw
  	cache: ghcr.io/galoisinc/cache-saw
  	- file: saw-remote-api/Dockerfile
  	image: ghcr.io/galoisinc/saw-remote-api
  	cache: ghcr.io/galoisinc/cache-saw-remote-api

• Deduplicate / normalize build and publish logic:
  
• Make sure release branches are getting verified correctly: https://github.com/GaloisInc/saw-script/actions/runs/766144193

Closes #1184

• Cryptol binaries are no longer included in release tarballs:

  $ ls saw-0.7.0.99-Linux-x86_64/bin
  saw  saw-remote-api
  

Closes #982

• Clean version numbers for release:

   ┏━━━┓━━━┓━┓━┓━┓
   ┃ ━━┓ ╻ ┃ ┃ ┃ ┃
   ┣━━ ┃ ╻ ┃┓ ╻ ┏┛
   ┗━━━┛━┛━┛┗━┛━┛ version 0.7.0.99 (6556792)