replace run-parts with find|sort to avoid debianutils usage

After e75e5879 the reason for an implicit dependency on debianutils
(which is essential for debian, but likely not on other systems) was
just two uses of run-parts, which can be replaced with the a lot more
portable find-piped-into-sort duo.

cmdline/apt-key.in

@@ -220,7 +220,7 @@ foreach_keyring_do() {
 	    if [ "${STRIPPED_TRUSTEDPARTS}/" = "$TRUSTEDPARTS" ]; then
 		TRUSTEDPARTS="$STRIPPED_TRUSTEDPARTS"
 	    fi
-	    for trusted in $(run-parts --list "$TRUSTEDPARTS" --regex '^.*\.gpg$'); do
+	    for trusted in $(find "$TRUSTEDPARTS" -mindepth 1 -maxdepth 1 -regex '^.*\.gpg$' | sort); do
 		if [ -s "$trusted" ]; then
 		    $ACTION "$trusted" "$@"
 		fi

test/integration/run-tests

@@ -83,7 +83,7 @@ PASS=0
 ALL=0
 FAILED_TESTS=""
 DIR="$(readlink -f "$(dirname "$0")")"
-TESTLIST="$(run-parts --list "$DIR" --regex '^test-.*$')"
+TESTLIST="$(find "$DIR" -mindepth 1 -maxdepth 1 -regex '^.*/test-[^/]*$' | sort)"
 if [ -n "$APT_TEST_JOBS" ]; then
 	if [ "$MSGCOLOR" != 'NO' ]; then
 		export MSGCOLOR='ALWAYS'