The current version of GCC in brew for macOS is gcc-13, but install-deps.sh explicitly exports CC=gcc-11 in install_osx(), which is not found and causes the swig configure to fail.

Unfortunately, I think you need to list all the versions of gcc that brew has installed and pick the latest one.

Here's a diff of the change that worked for me:

diff --git a/install-deps.sh b/install-deps.sh
index 6aa6d480..e17262ec 100755
--- a/install-deps.sh
+++ b/install-deps.sh
@@ -81,7 +81,8 @@ install_osx() {
   brew install --cask xquartz mactex
   export PATH="/Library/TeX/texbin:$PATH"
   brew link --overwrite gcc
-  export CC=gcc-11
+  INSTALLED_GCC=$(basename $(ls /usr/local/bin/gcc-* | /usr/bin/grep -E 'gcc-[0-9]+$' | /usr/bin/sort --version-sort | /usr/bin/tail -1))
+  CC=$INSTALLED_GCC
 #  (cd /usr/local/Cellar/gcc/8.2.0/lib/gcc/8/gcc/x86_64-apple-darwin17.7.0/8.2.0/include-fixed && mv stdio.h stdio.h.botched)
 }