Fix duplicate word in A01 description

[sainadh777]

Summary

• remove the duplicated or from the A01:2025 elevation-of-privilege description
• preserve the sentence's intended meaning and all surrounding content

Root cause

The English A01:2025 source contained a duplicated conjunction (or or), which was carried unchanged into the generated site.

Impact

Readers now see the grammatically correct description. This is a documentation-only change with no application or security behavior impact.

Corner cases

• the duplicated phrase occurred once in the relevant source
• only the English 2025 page is changed; translations and historical editions are untouched
• no links, navigation entries, anchors, or generated assets are changed

Validation

• git diff --check and git diff --cached --check — passed with 0 errors
• source and rendered-content checks with rg — passed; the corrected phrase appears and or or is absent
• (cd 2025 && ../venv/bin/mkdocs build --clean --site-dir /tmp/owasp-top10-issue-961.JDKqVn) — passed in 14.43 seconds and generated 215 files, with 0 build errors and 1 pre-existing MkDocs configuration warning plus 1 LibreSSL environment notice
• npx --yes markdownlint-cli@0.26.0 2025/docs/en/A01_2025-Broken_Access_Control.md — reported 119 existing style violations; the upstream/master version reports the same 119, so this change adds 0 violations
• local browser smoke test of /A01_2025-Broken_Access_Control/ — page and core assets returned HTTP 200; the corrected sentence was visible exactly once, the duplicated phrase was absent, and the browser console reported 0 warnings/errors. Nine generated language-specific sitemap.xml requests returned pre-existing 404s from unchanged site configuration.

Fixes #961

[sainadh777]

Closing to avoid overlapping active work: #917 and #904 already implement this same one-line correction.