Fix svg files not being compressed

[Degubi]

PR Type

Bug Fix

PR Checklist

• Tests for the changes have been added / updated.
• Documentation comments have been added / updated.
• A changelog entry has been made for the appropriate packages.
• Format code with the latest stable rustfmt.
• (Team) Label with affected crates and semver status.

Overview

#3075 removed compression for image & video files, because they usually come pre-compressed.
SVG (image/svg+xml) files are exceptions (IMO), because they're text based, so they could benefit from being served as compressed assets.

Note 1: I wasn't sure whether to add a test or not.
Note 2: I wasn't able to test this change because I was getting a wall of seemingly unrelated 'unresolved imports' errors in my project after switching to my fork in the Cargo.toml.

[Degubi]

Not really sure about the 'Linux / msrv actix-files tests::test_head_content_length_headers' test failure, because afaict I didn't touch anything that could cause that test to fail.

About the 'public-api-diff' I saw that another PR was failing with the same error message as this PR:

This version of `cargo public-api` requires at least:
    nightly-2024-10-18
Ensure your nightly toolchain is up to date with:
    rustup install nightly --profile minimal