Support Python 3.11 and PostgreSQL 15. This release also drops support
for Python 3.6.

Changes

• Add arm64 mac and linux wheels
  (by @ddelange in 7bd6c49 for #954)

• Add Python 3.11 to the test matrix
  (by @elprans in 5f908e6 for #948)

• Exclude .venv from flake8 (#958)
  (by @jparise in 40b16ea for #958)

• Upgrade to flake8 5.0.4 (from 3.9.2) (#961)
  (by @jparise in 0e73fec for #961)

• Show an example of a custom Record class (#960)
  (by @jparise in 84c99bf for #960)

• Use the exact type name in Record.repr (#959)
  (by @jparise in eccdf61 for #959)

• Drop Python 3.6 support (#940)
  (by @bryanforbes in bb0cb39 for #940)

• Test on Python 3.11 and PostgreSQL 15, fix workflow deprecations (#968)
  (by @elprans in eab7fdf for #968)