After new release git 2.39.1 ubuntu version git-crypt not working merge command

Hi,

After to updated git version to 2.39.1 ubuntu focal version the git-crypt not working for merge command.

```sh
> GIT_CURL_VERBOSE=1 GIT_TRACE=1 git merge master
14:35:12.818355 git.c:460 trace: built-in: git merge master
14:35:12.998825 run-command.c:655 trace: run_command: '"git-crypt" clean'
14:35:13.003634 git.c:460 trace: built-in: git rev-parse --git-dir
14:35:13.008099 run-command.c:655 trace: run_command: git stash create
14:35:13.010771 git.c:460 trace: built-in: git stash create
14:35:13.017251 run-command.c:655 trace: run_command: '"git-crypt" clean'
14:35:13.022418 git.c:460 trace: built-in: git rev-parse --git-dir
fatal: stash failed

```

My config `.git/config` file

```sh
[...]
[filter "git-crypt"]
smudge = \"git-crypt\" smudge
clean = \"git-crypt\" clean
required = true
[diff "git-crypt"]
textconv = \"git-crypt\" diff
[...]
```

Any idea for bug git-crypt?