Release 0.1.5-1

Security-focused dependency refresh:

• markitdown[all] 0.1.2 → 0.1.5 — includes upstream CVE fixes for mammoth
  (CVE-2025-11849) and pdfminer.six (GHSA-wf5f-4jwr-ppcp)
• fastapi 0.115.12 → 0.136.3 (CVE-2026-48710)
• python-multipart 0.0.20 → 0.0.29
• uvicorn 0.34.0 → 0.48.0

Why markitdown 0.1.5 and not 0.1.6?
0.1.6 pulls in a pre-release Azure SDK we don't want in production.

Docker image:

docker pull ghcr.io/dezoito/markitdown-api:0.1.5-1