I have observed that this error usually happens when you install via conda/mamba but the order of channels is incorrect. So try the following:

# Uninstall samtools
conda remove samtools

# Set the proper channel order
conda config --prepend channels conda-forge
conda config --append channels bioconda

# Set the channel priority
conda config --set channel_priority strict

# Reinstall samtools
conda install samtools

You may need to update all packages in case other packages have troubles.

conda update --all