configure CI so it doesnt install dependencies and compile the contracts for every step

[0xteddybear]

the current CI setup

• configures node
• installs foundry
• installs dependencies with yarn
• and finally builds the project

for every step such as running integration tests, running unit tests, and the various static analysis tools

we could reduce the gh runner time we spend if we only did that setup once (albeit that might reduce paralelism and, for example, omit to run tests if a linter fails)

update: after a quick conversation with @0xGorilla , I understood it was deliberate decision to run the setup multiple times as it was highly desireable for the rest of the checks to

• run in parallel
• be independent of each other

so this will be implemented only if we can maintain the two properties above