fix(deployer): add content-encoding if mimetypes infers one

[yin1999]

Summary

Fixes: #8497

Problem

The content-encoding of sitemap files, such as: https://developer.mozilla.org/sitemaps/en-us/sitemap.xml.gz is not set.

Solution

Add content-encoding when mimetypes could infer this.

Some refs:

• S3 adapter: upload with "content-type" and "content-encoding" headers kjvarga/sitemap_generator#338
• https://docs.python.org/3.10/library/mimetypes.html#mimetypes.guess_type
• https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/s3/client/upload_file.html
• https://boto3.amazonaws.com/v1/documentation/api/latest/reference/customizations/s3.html#boto3.s3.transfer.S3Transfer

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Screenshots

None.

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How did you test this change?

The content-encoding and content-type inferred by mimetypes.

[caugner]

Triggered a stage-build to test your changes. Once that's finished, https://developer.allizom.org/sitemaps/en-us/sitemap.xml.gz should display properly.

[caugner]

Once that's finished, https://developer.allizom.org/sitemaps/en-us/sitemap.xml.gz should display properly.

While https://developer.allizom.org/sitemaps/en-us/sitemap.xml.gz displays properly, https://developer.allizom.org/sitemaps/fr/sitemap.xml.gz doesn't. 🤔

But it turns out this is just a side-effect of our deployer only uploading modified files, not taking into consideration the changed metadata. For example, https://developer.allizom.org/sitemaps/ja/sitemap.xml.gz also works.

So I'll go ahead and merge this, even though we're finishing up our migration to GCP in the upcoming weeks, thank you @yin1999!