fix: plugin ideal-image should generate filename with a hash even in development

[Pierre-Gilles]

Hi! Following our discussion here (#5326), I wrote a PR to generate hash filename even in dev environnement.

I've run the test suites, linter & prettier and it seems fine. I've started the Docusaurus website locally as well.

I haven't found any tests for this plugin so I don't know if I should write some?

Have you read the Contributing Guidelines on pull requests?

Yes

[netlify]

✔️ [V2]
Built without sensitive environment variables

🔨 Explore the source changes: 4d59a85

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[github-actions]

⚡️ Lighthouse report for the changes in this PR:

Category	Score
🟢 Performance	91
🟢 Accessibility	98
🟢 Best practices	100
🟢 SEO	100
🟢 PWA	95

Lighthouse ran on https://deploy-preview-5334--docusaurus-2.netlify.app/

[slorber]

Thanks 👍

I haven't found any tests for this plugin so I don't know if I should write some?

Not sure there's a good way to unit test this anyway. We have some e2e test that fails if yarn start has webpack errors/warnings in our own website so the best test could be to dogfood your use-case and add 2 images of the same name to our website. Not sure it's really worth it.