Revert "fix: use git dates by default, @napi/git is fast enough"

This reverts commit 5dcb7e83fc.

quartz.config.ts

@@ -47,7 +47,7 @@ const config: QuartzConfig = {
       Plugin.FrontMatter(),
       Plugin.TableOfContents(),
       Plugin.CreatedModifiedDate({
-        priority: ["frontmatter", "git", "filesystem"],
+        priority: ["frontmatter", "filesystem"], // you can add 'git' here for last modified from Git but this makes the build slower
       }),
       Plugin.SyntaxHighlighting(),
       Plugin.ObsidianFlavoredMarkdown({ enableInHtmlEmbed: false }),