v4.7.1: Upgrade & pin WS dependency to v8 to resolve upstream regression

What's Changed

• chore(): upgrade GitHub Actions to setup-node v7 and checkout v6 by @JJ-Cro in #557
• fix(v4.7.1, #558): ws v7 dependency WS_ERR_TOO_MANY_BUFFERED_PARTS side effect, chore: remove bundle analyser, fix: return type by @tiagosiebler in #559

Full Changelog: v4.7.0...v4.7.1