Images should contain subdirectory for version

This is to help for the libpath problem that snekbox is experiencing
because the default library search path is changed when we copy files.

Author: jb3

scripts/build_python.sh

@@ -4,19 +4,29 @@ shopt -s inherit_errexit
 
 py_version="${1}"
 
+# Install Python interpreter under e.g. /snekbin/python/3.13/ (no patch version)
+# By dropping everything after, and including, the last period or hyphen.
+install_path="${py_version%[-.]*}"
+
+# Ensure the suffix letter is retained for free-threaded or JIT versions of Python.
+if [[ $py_version == *t ]]; then
+    install_path+="t"
+fi
+
 if [[ $py_version == *j ]]; then
     # Enable JIT mode when passed a version that ends with a "j"
+    install_path+="j"
     py_version="${py_version%j}"
     PYTHON_CONFIGURE_OPTS+=" --enable-experimental-jit"
 fi
 
 "${PYENV_ROOT}/plugins/python-build/bin/python-build" \
     "${py_version}" \
-    "/snekbin/"
-"/snekbin/bin/python" -m pip install -U pip
+    "/snekbin/python/${install_path}"
+"/snekbin/python/${install_path}/bin/python" -m pip install -U pip
 
 # Clean up some unnecessary files to reduce image size bloat.
-find /snekbin/ -depth \
+find /snekbin/python/ -depth \
 \( \
     \( -type d -a \( \
         -name test -o -name tests -o -name idle_test \