[Snyk] Security upgrade alpine from 3.18.3 to 3.21.0#86

pozgo wants to merge 1 commit intomasterpozgo/docker-mkdocs:masterfrom

snyk-fix-984876a5824e02bad66026927bd0e2f9pozgo/docker-mkdocs:snyk-fix-984876a5824e02bad66026927bd0e2f9Copy head branch name to clipboard