Replace single quotes with escaped double quotes

This fixes the behavior on Windows, which does not always recognize single quotes. This can lead to clangd failing to compile the database correctly.

R/compilation-db.R

@@ -268,5 +268,5 @@ linking_to_flags <- function(desc) {
   paths <- vapply(linking_to, function(pkg) system.file("include", package = pkg), "")
   paths <- paths[paths != ""]
 
-  paste(paste0("-I'", paths, "'"), collapse = " ")
+  paste(paste0("-I\"", paths, "\""), collapse = " ")
 }