lint: Skip whitespace lint for guix patches

test/lint/lint-whitespace.sh

@@ -33,7 +33,7 @@ if [ -z "${COMMIT_RANGE}" ]; then
 fi
 
 showdiff() {
-  if ! git diff -U0 "${COMMIT_RANGE}" -- "." ":(exclude)depends/patches/" ":(exclude)src/leveldb/" ":(exclude)src/crc32c/" ":(exclude)src/secp256k1/" ":(exclude)src/univalue/" ":(exclude)doc/release-notes/" ":(exclude)src/qt/locale/"; then
+  if ! git diff -U0 "${COMMIT_RANGE}" -- "." ":(exclude)depends/patches/" ":(exclude)contrib/guix/patches/" ":(exclude)src/leveldb/" ":(exclude)src/crc32c/" ":(exclude)src/secp256k1/" ":(exclude)src/univalue/" ":(exclude)doc/release-notes/" ":(exclude)src/qt/locale/"; then
     echo "Failed to get a diff"
     exit 1
   fi