Fix audit workflow

[tvpeter]

Description

Fixes #15 and #14

Updates Audit Workflow

Notes to the reviewers

• remove master branch filter
• fix invalid pinned SHA
• removed Swatinem/rust-cache action

Checklists

All Submissions:

• I've signed all my commits
• I followed the contribution guidelines
• I ran cargo fmt and cargo clippy before committing

[ValuedMammal]

I think issue #14 is referring to using actions-rust-lang/setup-rust-toolchain, with cache: true, as we are also using in cont_integration.yml, but don't know if I've missed something.

[oleonardolima]

I think issue #14 is referring to using actions-rust-lang/setup-rust-toolchain, with cache: true, as we are also using in cont_integration.yml, but don't know if I've missed something.

Yes, that's what I meant, instead of using the actions/cache and dtolnay/rust, we can just use the cache feature in the actions-rust-lang/setup-rust-toolchain.