Update dependency mkdocs-material to v9.6.15 (#2022)

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

Author: renovate[bot]

.github/workflows/requirements.txt

@@ -7,7 +7,7 @@ Markdown<3.9
 MarkupSafe==3.0.2
 mkdocs==1.6.1
 mkdocs-macros-plugin==1.3.7
-mkdocs-material==9.6.14
+mkdocs-material==9.6.15
 mkdocs-material-extensions==1.3.1
 Pygments==2.19.2
 pymdown-extensions==10.16