Update generated .gitignore

Now it also has the file with pattern `libname.a` filtered out, as that is what I get on my platform by default and it was missing.
For context, debian 13 and latest ldc2.

Author: KaruroChori

source/dub/init.d

@@ -190,6 +190,7 @@ docs/
 %1$s.so
 %1$s.dylib
 %1$s.dll
+lib%1$s.a
 %1$s.a
 %1$s.lib
 %1$s-test-*