chore(sync): merge upstream startup optimizations

zsh/pyenv.zsh

@@ -3,6 +3,8 @@ export PYENV_ROOT="${PYENV_ROOT:-$HOME/.pyenv}"
 [[ -d "$PYENV_ROOT/bin" ]] && path=("$PYENV_ROOT/bin" ${path:#$PYENV_ROOT/bin})
 [[ -d "$PYENV_ROOT/shims" ]] && path=("$PYENV_ROOT/shims" ${path:#$PYENV_ROOT/shims})
 export PATH
-if [[ -o interactive ]] && command -v pyenv &> /dev/null; then
-  eval "$(pyenv init - zsh)"
+# Login profiles can reapply PATH without repeating shell integration.
+# Run `pyenv rehash` after installing entry points through `python -m pip`.
+if [[ -o interactive ]] && (( ! $+functions[pyenv] )) && command -v pyenv &> /dev/null; then
+  eval "$(pyenv init - --no-rehash zsh)"
 fi