Add vscode workspace files to `.gitignore` (#15202)

diff --git a/.gitignore b/.gitignore
index c8c0b25..44b9530 100644
--- a/.gitignore
+++ b/.gitignore
@@ -13,6 +13,7 @@
 *.VC.opendb
 *.suo
 *.user
+*.code-workspace
 
 # macOS files
 .DS_Store