#1035 Update to release 3.8.0

Update to release 3.8.0

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Summary by cubic

Bumps the script and package versions from 3.7.2 to 3.8.0 and records 3.8.0 in the release notes. The release fixes a TypeError on error pages, adds compatibility with the new /web/contest page, and preserves problem Markdown (formulas, code, tables, links, and sample line breaks) when copying statements, including full-statement copying.

Summary by Sourcery

Release version 3.8.0.

Build:

• Update the project and userscript version metadata to 3.8.0.

Chores:

• Add the release update metadata for version 3.8.0.