perf: remove importChain when loading slide modules (#1652)

Co-authored-by: _Kerman <kermanx@qq.com>

packages/slidev/node/vite/loaders.ts

@@ -314,6 +314,7 @@ export function createSlidesLoader(
                 ...withRenderedNote(slide),
                 frontmatter: undefined,
                 source: undefined,
+                importChain: undefined,
                 // remove raw content in build, optimize the bundle size
                 ...(mode === 'build' ? { raw: '', content: '', note: '' } : {}),
               }