Release notes for v1.4.3

Changelog since v1.4.2

Changes by Kind

Bug or Regression

• Adds an explicit 10 second timeout when checking HTTP01 challenges for reachability (#4319, @SgtCoDFish)

Other (Cleanup or Flake)

• Clarify the exact supported kubernetes version range for cert-manager 1.4 (#4315, @SgtCoDFish)