`cat-file --filter` is broken in 2.50?

Hi,

`cat-file --filter` stopped working in git 2.50.

``` $ git version git version 2.47.1.windows.2

$ git cat-file --filter "HEAD:changelog.md" <content> ```

``` $ git version git version 2.50.0.windows.1

$ git cat-file --filter "HEAD:changelog.md" fatal: invalid filter-spec 'HEAD:changelog.md' ```

The problem was introduced at eb83e4c64b5a3458569593c2ab0c29365f10a82f.

Then it was merged into the main branch by a271b05066a1fd2c3a62508d9908d6c5df14a1cb.

This seems like a bug.