`git commit -a` is unable to remove the last file in the index in v2.41.0
comparing git version 2.30.2 to 2.41.0
```
$ git --version
git version 2.30.2
$ git init
Initialized empty Git repository in /tmp/tmp.vXqq6iVaqq/.git/
$ echo "foo" > a
$ git add a
$ git commit -m "C1"
[master (root-commit) b3abdc4] C1
1 file changed, 1 insertion(+)
create mode 100644 a
$ rm a
$ git commit -a -m "C2"
[master c3d4c44] C2
1 file changed, 1 deletion(-)
delete mode 100644 a
```
```
$ git --version
git version 2.41.0
$ git init
Initialized empty Git repository in /tmp/tmp.vXqq6iVaqq/.git/
$ echo "foo" > a
$ git add a
$ git commit -m "C1"
[master (root-commit) af7c07d] C1
1 file changed, 1 insertion(+)
create mode 100644 a
$ rm a
$ git commit -a -m "C2"
On branch master
Changes not staged for commit:
(use "git add/rm <file>..." to update what will be committed)
(use "git restore <file>..." to discard changes in working directory)
deleted: a
no changes added to commit (use "git add" and/or "git commit -a")
```
- Dylan Brotherston
