Building GCC 12.4, I get: libisl.so.23: ... No such file or directory

I'm trying to build GCC 12.4.0 on Oracle Linux 9.4 (sorry about that... not my choice of distribution), as a non-root user. So, I've downloaded and built my relevant prerequisites: gmp, mpfr, mpc, isl, installing them into their own separate directories. I now try:

-bash
./configure --disable-ada --disable-gnat --disable-fortran --disable-bootstrap \
    --disable-bootstrap --enable-languages=c,c++  \
    --prefix=$HOME/opt/versions/gcc/12.4.0 --with-gmp=$HOME/opt/gmp \
    --with-mpfr=$HOME/opt/mpfr --with-mpc=$HOME/opt/mpc --with-isl=$HOME/opt/isl

but this gives me:

--- snip ---
/home/lh156516/src/gcc/gcc-12.4.0/host-x86_64-pc-linux-gnu/gcc/xgcc -B/home/lh156516/src/gcc/gcc-12.4.0/host-x86_64-pc-linux-gnu/gcc/ -xc -nostdinc /dev/null -S -o /dev/null -fself-test=../.././gcc/testsuite/selftests
/home/lh156516/src/gcc/gcc-12.4.0/host-x86_64-pc-linux-gnu/gcc/xgcc -B/home/lh156516/src/gcc/gcc-12.4.0/host-x86_64-pc-linux-gnu/gcc/ -xc++ -nostdinc /dev/null -S -o /dev/null -fself-test=../.././gcc/testsuite/selftests
/home/lh156516/src/gcc/gcc-12.4.0/host-x86_64-pc-linux-gnu/gcc/cc1: error while loading shared libraries: libisl.so.23: cannot open shared object file: No such file or directory
make: *** [../.././gcc/c/Make-lang.in:128: s-selftest-c] Error 1
make: *** Waiting for unfinished jobs....
/home/lh156516/src/gcc/gcc-12.4.0/host-x86_64-pc-linux-gnu/gcc/cc1plus: error while loading shared libraries: libisl.so.23: cannot open shared object file: No such file or directory
make: *** [../.././gcc/cp/Make-lang.in:206: s-selftest-c++] Error 1
make: *** [Makefile:4619: all-gcc] Error 2
make: *** [Makefile:1034: all] Error 2

All of the prerequisite libraries have been built and installed to their specified ~/opt subdirectories, and I've verified that I indeed have $HOME/opt/isl/lib/libisl.so.23. So, why am I getting this error?