[Tests] update R, Python and Julia

[cderv]

This update

• R 4.6.1 and latest packages
• Python 3.14.7, latest uv and latest packages
• Julia 3.12.7 and update of packages

[posit-snyk-bot]

✅ Snyk checks have passed. No issues have been found so far.

Status	Scan Engine	Critical	High	Medium	Low	Total (0)
✅	Open Source Security	0	0	0	0	0 issues
✅	Licenses	0	0	0	0	0 issues

💻 Catch issues earlier using the plugins for VS Code, JetBrains IDEs, Visual Studio, and Eclipse.

[cderv]

CI was failing on docs/smoke-all/jupyter/image-dimensions/matplotlib-quarto-retina.qmd on both ubuntu-latest and windows-latest. Root cause: this PR's matplotlib bump (3.10.8 -> 3.11.1 in tests/uv.lock) shifted the tight-bbox crop width of that test's figure by one pixel (537 -> 538), so the hardcoded img[width="537"] assertion no longer matched. Reproduced locally with the updated env and confirmed the new correct value is 538. Fixed in 969bfe9 by updating the expected width.