Fix build with boost 1.83

https://github.com/mapnik/mapnik/commit/50f1b05f863ab7060558d91a7d9521d849f29df3

Index: plugins/input/csv/csv_utils.cpp
--- plugins/input/csv/csv_utils.cpp.orig
+++ plugins/input/csv/csv_utils.cpp
@@ -40,6 +40,9 @@
 #include <cstdio>
 #include <algorithm>
 
+// boost string algo
+#include <boost/algorithm/string/trim.hpp>
+
 namespace csv_utils {
 namespace detail {
 
