FATA[0000] lstat /Containerfile: no such file or directory

### Description

Using nerdctl (from Rancher Desktop v 1.18.2) to build a container doesn't find the local Dockerfile and seems to want a Containerfile at the root of the filesystem, not the current path.

Build succeeds using Git Bash on the same machine using the same command, so for now I context switch from rancher-desktop WSL to git bash to build and then back to rancher-desktop WSL to run.

### Steps to reproduce the issue

1. ls -al Dockerfile
`-rw-rw-rw- 1 root 0 151 May 23 06:33 Dockerfile`
2. nerdctl build -t db:20250523 .
`FATA[0000] lstat /Containerfile: no such file or directory`
3. pwd
`/mnt/c/Users/myuser/Documents/projects/couchdb`

### Describe the results you received and expected

```
[+] Building 2.1s (7/7)
[+] Building 2.2s (7/7) FINISHED
=> [internal] load build definition from Dockerfile 0.1s
=> => transferring dockerfile: 190B 0.0s
=> [internal] load metadata for docker.io/library/couchdb:3.4.2 0.3s
=> [internal] load .dockerignore 0.0s
=> => transferring context: 2B 0.0s
=> [internal] load build context 0.0s
=> => transferring context: 31B 0.0s
=> [1/2] FROM docker.io/library/couchdb:3.4.2@sha256:2817ad50b5c5cf7461f5963670466197426605a790a19a6208068c509a2d8a59 0.1s
=> => resolve docker.io/library/couchdb:3.4.2@sha256:2817ad50b5c5cf7461f5963670466197426605a790a19a6208068c509a2d8a59 0.0s
=> CACHED [2/2] COPY local.ini /opt/couchdb/etc/local.d 0.0s
=> exporting to docker image format 1.5s
=> => exporting layers 0.0s
=> => exporting manifest sha256:0cb940aa5b3847f2f1c9419f030e97e85f3d1fe390f6dcf2ca6214e12576e35d 0.0s
=> => exporting config sha256:fe79dc82c1b3e7612789f6f807bf5a8bd697c61e1055cbecc119eda1b07b7a8d 0.0s
=> => sending tarball 1.4s
Loaded image: docker.io/library/db:20250522
```

### What version of nerdctl are you using?

nerdctl version 2.0.3

### Are you using a variant of nerdctl? (e.g., Rancher Desktop)

Rancher Desktop for Windows

### Host information

Edition Windows 11 Pro
Version 24H2
Installed on ‎2025-‎02-‎22
OS build 26100.4061
Experience Windows Feature Experience Pack 1000.26100.84.0