Revert "Merge from vscode merge-base (#22769)" (#22779)

This reverts commit 6bd0a17d3c.

extensions/git/src/uri.ts

@@ -51,14 +51,3 @@ export function toGitUri(uri: Uri, ref: string, options: GitUriOptions = {}): Ur
 		query: JSON.stringify(params)
 	});
 }
-
-/**
- * Assuming `uri` is being merged it creates uris for `base`, `ours`, and `theirs`
- */
-export function toMergeUris(uri: Uri): { base: Uri; ours: Uri; theirs: Uri } {
-	return {
-		base: toGitUri(uri, ':1'),
-		ours: toGitUri(uri, ':2'),
-		theirs: toGitUri(uri, ':3'),
-	};
-}