chore(IDX): fix some shellcheck warnings in main.sh (#4053)

This removes an outdated comment and fixes some shellcheck warnings from
`ci/bazel-scripts/main.sh`.

ci/bazel-scripts/main.sh

@@ -58,9 +58,10 @@ if [ -n "${CLOUD_CREDENTIALS_CONTENT+x}" ]; then
     unset CLOUD_CREDENTIALS_CONTENT
 fi
 
-if [ -z "${KUBECONFIG:-}" ] && [ ! -z "${KUBECONFIG_TNET_CREATOR_LN1:-}" ]; then
-    export KUBECONFIG=$(mktemp -t kubeconfig-XXXXXX)
-    echo $KUBECONFIG_TNET_CREATOR_LN1 >$KUBECONFIG
+if [ -z "${KUBECONFIG:-}" ] && [ -n "${KUBECONFIG_TNET_CREATOR_LN1:-}" ]; then
+    KUBECONFIG=$(mktemp -t kubeconfig-XXXXXX)
+    export KUBECONFIG
+    echo "$KUBECONFIG_TNET_CREATOR_LN1" >"$KUBECONFIG"
     trap 'rm -f -- "$KUBECONFIG"' EXIT
 fi
 
@@ -102,14 +103,12 @@ if [[ ! " ${bazel_args[*]} " =~ [[:space:]]--repository_cache[[:space:]] ]] && [
     bazel_args+=(--repository_cache=/cache/bazel)
 fi
 
-# shellcheck disable=SC2086
-# ${BAZEL_...} variables are expected to contain several arguments. We have `set -f` set above to disable globbing (and therefore only allow splitting)"
 bazel "${bazel_args[@]}" 2>&1 | awk -v url_out="$url_out" "$stream_awk_program"
 
 # Write the bes link & summary
 echo "Build results uploaded to $(<"$url_out")"
 if [ -n "${GITHUB_STEP_SUMMARY:-}" ]; then
     invocation=$(sed <"$url_out" 's;.*/;;') # grab invocation ID (last url part)
-    echo "BuildBuddy [$invocation]($(<"$url_out"))" >>$GITHUB_STEP_SUMMARY
+    echo "BuildBuddy [$invocation]($(<"$url_out"))" >>"$GITHUB_STEP_SUMMARY"
 fi
 rm "$url_out"