[Product Update] Speeding up code checkout

Thanks. I already got helped out by Sebastian Lerner.

Based on aggregate feedback and the issues encountered, we have rolled back blobless clones. Checkout steps will return to the original functionality prior to Jan 25.

Follow future developments here if desired: Allow for Shallow Clone command in 2.0 | Feature Requests | CircleCI Ideas

Any future breaking changes will be announced via email in advance.