vagrant: use Python 3.9.5

Vagrantfile

@@ -136,7 +136,7 @@ end
 def install_pythons(boxname)
   return <<-EOF
     . ~/.bash_profile
-    pyenv install 3.9.1  # tests, version supporting openssl 1.1, binary build
+    pyenv install 3.9.5  # tests, version supporting openssl 1.1, binary build
     pyenv install 3.8.0  # tests, version supporting openssl 1.1
     pyenv install 3.7.0  # tests, version supporting openssl 1.1
     pyenv install 3.6.2  # tests, version supporting openssl 1.1. broken for older 3.6.x.
@@ -157,8 +157,8 @@ def build_pyenv_venv(boxname)
     . ~/.bash_profile
     cd /vagrant/borg
     # use the latest 3.9 release
-    pyenv global 3.9.1
-    pyenv virtualenv 3.9.1 borg-env
+    pyenv global 3.9.5
+    pyenv virtualenv 3.9.5 borg-env
     ln -s ~/.pyenv/versions/borg-env .
   EOF
 end
@@ -207,8 +207,8 @@ def run_tests(boxname, skip_env)
     . ../borg-env/bin/activate
     if which pyenv 2> /dev/null; then
       # for testing, use the earliest point releases of the supported python versions:
-      pyenv global 3.6.2 3.7.0 3.8.0 3.9.1
-      pyenv local 3.6.2 3.7.0 3.8.0 3.9.1
+      pyenv global 3.6.2 3.7.0 3.8.0 3.9.5
+      pyenv local 3.6.2 3.7.0 3.8.0 3.9.5
     fi
     # otherwise: just use the system python
     # some OSes can only run specific test envs, e.g. because they miss FUSE support: