Update go.mod files to go1.18, update license vendor script

hack/update-vendor-licenses.sh

@@ -186,8 +186,10 @@ if [ -f "${LICENSE_ROOT}/LICENSE" ]; then
   mv "${TMP_LICENSE_FILE}" "${TMP_LICENSES_DIR}/LICENSE"
 fi
 
+# Capture all module dependencies
+modules=$(go list -m -json all | jq -r .Path | sort -f)
 # Loop through every vendored package
-for PACKAGE in $(go list -m -json all | jq -r .Path | sort -f); do
+for PACKAGE in ${modules}; do
   if [[ -e "staging/src/${PACKAGE}" ]]; then
     echo "${PACKAGE} is a staging package, skipping" >&2
     continue
@@ -196,26 +198,16 @@ for PACKAGE in $(go list -m -json all | jq -r .Path | sort -f); do
     echo "${PACKAGE} doesn't exist in ${DEPS_DIR}, skipping" >&2
     continue
   fi
-  # Skip a directory if 1) it has no files and 2) all the subdirectories contain a go.mod file.
-  misses_go_mod=false
-  DEPS_SUBDIR="${DEPS_DIR}/${PACKAGE}"
-  search_for_mods () {
-    if [[ -z "$(find "${DEPS_SUBDIR}/" -mindepth 1 -maxdepth 1 -type f)" ]]; then
-      while read -d "" -r SUBDIR; do
-          if [[ ! -e "${SUBDIR}/go.mod" ]]; then
-              DEPS_SUBDIR=${SUBDIR}
-              search_for_mods
-          fi
-      done < <(find "${DEPS_SUBDIR}/" -mindepth 1 -maxdepth 1 -type d -print0)
-    else
-      misses_go_mod=true
-    fi
-  }
-  search_for_mods
-  if [[ $misses_go_mod = false ]]; then
-      echo "${PACKAGE} has no files, skipping" >&2
+
+  # if there are no files vendored under this package...
+  if [[ -z "$(find "${DEPS_DIR}/${PACKAGE}" -mindepth 1 -maxdepth 1 -type f)" ]]; then
+    # and we have the same number of submodules as subdirectories...
+    if [[ "$(find "${DEPS_DIR}/${PACKAGE}/" -mindepth 1 -maxdepth 1 -type d | wc -l)" -eq "$(echo "${modules}" | grep -cE "^${PACKAGE}/")" ]]; then
+      echo "Only submodules of ${PACKAGE} are vendored, skipping" >&2
       continue
+    fi
   fi
+
   echo "${PACKAGE}"
 
   process_content "${PACKAGE}" LICENSE