lttoolbox: Add upstream patch, remove workaround

Author: Dave-Allured

textproc/lttoolbox/Portfile

@@ -32,13 +32,9 @@ checksums               rmd160  81acb8547ecebd9a1ca335ae4cd949bd76e8df8c \
                         sha256  7028dbbcda6c49467378d47784092ef8aba9a59d53e78102742d1edb7c5ff21b \
                         size    157342
 
-# 2025 Nov 29:  lttoolbox version 3.8.2:
-# Fails on macos 26 CI when -std=c++23 is enabled.
-# Explicitly downgrade the C++ standard until upstream is fixed.
+# Fixed upstream.  Remove when fixed after version 3.8.2.
 # https://github.com/apertium/lttoolbox/issues/206
-
-cmake.set_cxx_standard  yes
-compiler.cxx_standard   2017
+patchfiles-append       patch-ustring_h.diff
 
 depends_build-append    path:bin/pkg-config:pkgconfig \
                         port:utfcpp