Dependabot removes version suffix in requirements.txt

### Is there an existing issue for this?

- [X] I have searched the existing issues

### Package ecosystem

pip

### Package manager version

Not applicable, but pip `21.1.1` on my local machine

### Language version

Not applicable, but Python `3.8` on my local machine

### Manifest location and content before the Dependabot update

`/requirements.lambda.txt`:
```
deskew==0.10.37
opencv-python-headless==4.5.3.56
shapely==1.8.0
numpy==1.24.4

-f https://download.pytorch.org/whl/torch_stable.html
Pillow==9.3.0
torch==1.9.1+cpu
torchvision==0.10.1+cpu

-f https://dl.fbaipublicfiles.com/detectron2/wheels/cpu/torch1.9/index.html
detectron2==0.6

python-dotenv==0.15.0
python-multipart==0.0.6
fastapi==0.70.0
mangum==0.17.0
```

### dependabot.yml content

Probably unrelated but I'll still provide it:
```yaml
version: 2

updates:
- package-ecosystem: github-actions
directory: /
schedule:
interval: daily
time: '11:00'
timezone: Europe/Vienna
```

### Updated dependency

`torch` from `1.9.1+cpu` to `1.13.1`

### What you expected to see, versus what you actually saw

The line for `torch` in `requirements.lambda.txt` should turn from this:
```
torch==1.9.1+cpu
```
into this:
```
torch==1.13.1+cpu
```
but it instead turned into this:
```
torch==1.13.1
```

### Native package manager behavior

Not applicable, since `pip` does not have this feature

### Images of the diff or a link to the PR, issue, or logs


### Smallest manifest that reproduces the issue

```
-f https://download.pytorch.org/whl/torch_stable.html
torch==1.9.1+cpu
```