🐛 fix(activation): silence deactivate hash -r under set -e (#3152)

Sourcing the bash/zsh activation script and later running `deactivate`
could abort the shell when strict mode is on. 🐚 Under `set -euo
pipefail` with shell command hashing disabled (`set +h`), the `hash -r`
call inside `deactivate()` returns non-zero, and `2>/dev/null` only
hides its stderr, not its exit status, so the failing command tears down
the session.

The `deactivate()` call now appends `|| true`, the same guard the
trailing activation-time `hash -r` already carried. This brings the two
`hash -r` sites into line and mirrors the equivalent CPython `venv`
change in gh-149701.

The fix is confined to the bash/zsh activator; behavior under non-strict
shells is unchanged since `hash -r` already succeeded there.

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Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>