Update dependency pip to v26.1 [SECURITY] (#1902)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

visual-retrieval-colpali/src/legacy-requirements.txt

@@ -289,7 +289,7 @@ pillow==12.2.0
     #   pdf2image
     #   sentence-transformers
     #   vidore-benchmark
-pip==26.0
+pip==26.1
     # via visual-retrieval-colpali (pyproject.toml)
 polars==1.9.0
     # via mteb