Not compatible with OpenTofu providers

### tf-migrate version

1.0.1

### Migration path

v4 to v5

### Affected resource type(s)

_No response_

### Description

Running:

```sh
~/Downloads/tf-migrate_1.0.1_linux_amd64/tf-migrate migrate --source-version v4 --target-version v5 --dry-run
```

### Input configuration

In my `.terraform.lock.hcl`:

```hcl
provider "registry.opentofu.org/cloudflare/cloudflare" {
version = "4.52.7"
constraints = "~> 4.0"
hashes =
...
```

### Expected output

```hcl

```

### Actual output

Gives:

```
DRY RUN MODE - No changes will be made
Error: no Cloudflare provider found in .terraform.lock.hcl
```

### Steps to reproduce

_No response_

### Additional context

```
tofu -version
OpenTofu v1.10.9
on linux_amd64
+ provider registry.opentofu.org/cloudflare/cloudflare v4.52.7
...
```