release: univer.sheet升级到0.6.9

Author: zhaijunlei955

src/components/BootstrapBlazor.UniverSheet/wwwroot/univer/univer-sheet.bundle.css

@@ -9,9 +9,9 @@
     overflow: hidden;
 }
 
-.univer-fixed {
+/* .univer-fixed {
     position: absolute;
-}
+} */
 
 .univer-theme {
     position: relative;