Spellcheck: ignore svg files by default

Migrated issue

Reported by: grimreaper

Related to !239 (merged)

Problem/Motivation

When adding SVG icons in projects, like in #3426449: Update styles declaration to use UI Styles sources or https://www.drupal.org/project/sobki_profile_bootstrap, it raises Spellcheck warnings because it is scanned.

Instead of adding the words in the project dictionary (like in https://www.drupal.org/project/sobki_profile_bootstrap) maybe it will be better to exclude svg files by default.

Steps to reproduce

Commit SVG files to a repository.

Proposed resolution

Exclude SVG files by default

Remaining tasks

Agree if ok to add such feature.
If yes, in Gitlab templates or in core cspell config?
Provide MR

Related issue: Issue #3426449