Every time I attempt to update or install a package in my base environment, the install fails with the error InvalidSpec: The package "nvidia/linux-64::cuda-toolkit==12.6.2=0" is not available for the specified platform.
Attempting to run conda remove cuda-toolkit eventually results in failing to verify the transaction with the error RemoveError: 'zstandard' is a dependency of conda and cannot be removed from conda's operating environment, despite zstandard not being in the list of packages that will be uninstalled. conda list also shows zstandard to be installed within the environment.
Both of these errors occur regardless of which solver is used, and --no-deps, --force, and similar flags also have no effect.