security: Run zizmor on CI, resolve actions#6721

nellshamrell merged 3 commits intorust-lang:masterrust-lang/this-week-in-rust:masterfrom

andrewpollack:andrewpollack/zizmor-auditandrewpollack/this-week-in-rust:andrewpollack/zizmor-auditCopy head branch name to clipboard