Upgrade Pandas from 1.1.3

Pandas is pinned at version 1.1.3, which is quite old now, being released in October 2020. Besides not being able to take advantage of many new Pandas features and bug fixes, this is also an issue for local development on Apple silicon machines.

Without any pre-compiled wheels available for `macos_*_arm64` (see #194), local development requires building Pandas from source. We've found that this is not possible on Macbooks for Pandas 1.1.3. This has been fixed starting with Pandas 1.3.0, which we can confirm can be built from source. However this means running a different version of Pandas in dev environments from the production container, which is obviously not ideal.