Prepare release of 0.8.0 alpha.5

[FabijanC]

Usage related changes

• Closes cairo-migrate can be removed #407
• integrated-devnet defaults to starknet-devnet 0.6.3
• Parts of documentation are improved and simplified (especially Cairo 0 compilation).

Development related changes

• Updates internal tools:
  • cairo compiler to 2.2.0
  • scarb to 0.7.0
  • starknet-devnet to 0.6.3

Checklist:

• Formatted the code
• No linter errors + tried to avoid introducing linter warnings
• Performed a self-review of the code
• Rebased to the last commit of the target branch (or merged it into my branch)
• Documented the changes
• Updated the test directory (with a test case consisting of network.json, hardhat.config.ts, check.ts)
• Linked issues which this PR resolves
• Created a PR to the plugin branch of starknet-hardhat-example:
  • Prepare release of plugin 0.8.0-alpha.5 starknet-hardhat-example#126
  • Modified test.sh to use my example repo branch
  • Restored test.sh to to use the original branch (after the example repo PR has been merged)
• All tests are passing (for external contributors who don't have access to the CI/CD pipeline)

[penovicp]

One typo, otherwise lgtm