fix: use full path /usr/include/sqlite3.h in CSQLite module map

Bare 'sqlite3.h' requires pkg-config to resolve the include path.
Using the absolute path works reliably on Linux after libsqlite3-dev
is installed, without depending on pkg-config being configured.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: vkuttyp

Sources/CSQLite/module.modulemap

@@ -1,5 +1,5 @@
 module CSQLite [system] {
-    header "sqlite3.h"
+    header "/usr/include/sqlite3.h"
     link "sqlite3"
     export *
 }