No longer apply cpp20 fixes to nightly-build now that they are in main

Revert "Apply cpp20 fixes from Xanthos to nightly build"

This reverts commit 9462dca.

Author: jdblischak

.github/scripts/nightly/cpp20.patch

@@ -16,9 +16,5 @@ sed -i \
   s/"tiledb rc"/"tiledb nightlies"/ \
   recipe/conda_build_config.yaml
 
-# Apply patch from Xanthos to support C++20
-# https://github.com/TileDB-Inc/tiledbsoma-feedstock/pull/246
-patch -p1 < .github/scripts/nightly/cpp20.patch
-
 # Print differences
 git --no-pager diff conda-forge.yml recipe/conda_build_config.yaml