Bump mamba from 2.0.5 to 2.0.8

Bumps [mamba](https://github.com/mamba-org/mamba) from 2.0.5 to 2.0.8.
- [Release notes](https://github.com/mamba-org/mamba/releases)
- [Commits](https://github.com/mamba-org/mamba/compare/micromamba-2.0.5...2.0.8)

repo2docker/buildpacks/conda/install-base-env.bash

@@ -5,7 +5,7 @@ set -ex
 
 cd $(dirname $0)
 
-export MAMBA_VERSION="2.0.5"
+export MAMBA_VERSION="2.0.8"
 export CONDA_VERSION=24.11.0
 
 URL="https://anaconda.org/conda-forge/micromamba/${MAMBA_VERSION}/download/${CONDA_PLATFORM}/micromamba-${MAMBA_VERSION}-0.tar.bz2"

tests/conda/py35-binder-dir/verify

@@ -16,10 +16,10 @@ v = out.split()[1]
 assert v[:3] == "3.5", out
 
 out = sh(["micromamba", "--version"])
-assert out == "2.0.5", out
+assert out == "2.0.8", out
 
 out = sh(["mamba", "--version"])
-assert out == "2.0.5", out
+assert out == "2.0.8", out
 
 
 sh([kernel_python, "-c", "import numpy"])