How to run in lint only (no fixing) mode

Hi!

I have the following action

```
name: Test PNPM dependencies are in sync across packages

on:
push:
paths:
- src/pnpm-lock.yaml
- src/pnpm-workspace.yaml
- .syncpackrc.json
- .github/workflows/test-pnpm-synced-dependencies.yml

jobs:
check-pnpm-lock-versions:
runs-on: ubuntu-22.04
name: Test PNPM dependencies are in sync across packages
steps:
- uses: actions/checkout@v3
- uses: actions/setup-node@v3
with:
node-version: 16
- uses: JamieMason/syncpack-github-action@0.2.2
with:
package-manager: "pnpm"
format-mismatches: "ignore"
lockfile-mismatches: "ignore"
semver-range-mismatches: "ignore"
version-mismatches: "lint"
```

Basically it should be lint only, no fixing mode. But when I try to run it it gives the following error


Start by reproducing the workflow with JamieMason/syncpack-github-action@0.2.2 and its version-mismatches input; the reported error is only provided as an image. Confirm the action can run in lint-only mode and that mismatches are reported without fixing files.

Written by the indexing model from the issue text.