gh-111501: Do not export PS1 in venv activate

PS1 is a parameter special to the current interactive shell. It does not
need to be exported to the environment. Exporting PS1 is not useful, and
will break different shells spawned by the current interactive shell.

Author: rpigott

Lib/venv/scripts/common/activate

@@ -20,7 +20,6 @@ deactivate () {
 
     if [ -n "${_OLD_VIRTUAL_PS1:-}" ] ; then
         PS1="${_OLD_VIRTUAL_PS1:-}"
-        export PS1
         unset _OLD_VIRTUAL_PS1
     fi
 
@@ -67,7 +66,6 @@ fi
 if [ -z "${VIRTUAL_ENV_DISABLE_PROMPT:-}" ] ; then
     _OLD_VIRTUAL_PS1="${PS1:-}"
     PS1="(__VENV_PROMPT__) ${PS1:-}"
-    export PS1
 fi
 
 # Call hash to forget past commands. Without forgetting

Misc/NEWS.d/next/Tools-Demos/2024-06-17-13-52-04.gh-issue-111501.syFLAV.rst

@@ -0,0 +1 @@
+PS1 is no longer exported by venv activate script