Fix bazel_skylib with Bazel@HEAD (#538)

tests/diff_test/diff_test_tests.sh

diff --git a/tests/diff_test/diff_test_tests.sh b/tests/diff_test/diff_test_tests.sh
index 9fffcc6..8f72c47 100755
--- a/tests/diff_test/diff_test_tests.sh
+++ b/tests/diff_test/diff_test_tests.sh
@@ -112,7 +112,21 @@
     path = "../ext2",
 )
 eof
-
+  cat >"$ws/main/MODULE.bazel" <<'eof'
+local_repository = use_repo_rule("@bazel_tools//tools/build_defs/repo:local.bzl", "local_repository")
+local_repository(
+    name = "bzl",
+    path = "../bzl",
+)
+local_repository(
+    name = "ext1",
+    path = "../ext1",
+)
+local_repository(
+    name = "ext2",
+    path = "../ext2",
+)
+eof
   # @ext1 has source files
   touch "$ws/ext1/WORKSPACE"
   echo 'exports_files(["foo.txt"])' >"$ws/ext1/foo/BUILD"
@@ -181,17 +195,17 @@
   (cd "$ws/main" && \
    bazel test ${flags} //:different1 --test_output=errors 1>"$TEST_log" 2>&1 \
      && fail "expected failure" || true)
-  expect_log 'FAIL: files "external/ext1/foo/foo.txt" and "external/ext2/foo/bar.txt" differ'
+  expect_log 'FAIL: files "external/.*ext1/foo/foo.txt" and "external/.*ext2/foo/bar.txt" differ'
 
   (cd "$ws/main" && \
    bazel test ${flags} //:different2 --test_output=errors 1>"$TEST_log" 2>&1 \
      && fail "expected failure" || true)
-  expect_log 'FAIL: files "external/ext1/foo/foo.txt" and "ext1/foo/foo.txt" differ'
+  expect_log 'FAIL: files "external/.*ext1/foo/foo.txt" and "ext1/foo/foo.txt" differ'
 
   (cd "$ws/main" && \
    bazel test ${flags} //:different3 --test_output=errors 1>"$TEST_log" 2>&1 \
      && fail "expected failure" || true)
-  expect_log 'FAIL: files "ext2/foo/foo.txt" and "external/ext2/foo/foo.txt" differ'
+  expect_log 'FAIL: files "ext2/foo/foo.txt" and "external/.*ext2/foo/foo.txt" differ'
 }
 
 function test_simple_diff_test_with_legacy_external_runfiles() {

tests/unittest_test.sh

diff --git a/tests/unittest_test.sh b/tests/unittest_test.sh
index 271f156..e0454f9 100755
--- a/tests/unittest_test.sh
+++ b/tests/unittest_test.sh
@@ -49,14 +49,20 @@
   local -r pkg="$1"
   mkdir -p "$pkg"
   cd "$pkg"
-
   cat > WORKSPACE <<EOF
 workspace(name = 'bazel_skylib')
-
 load("//lib:unittest.bzl", "register_unittest_toolchains")
-
 register_unittest_toolchains()
 EOF
+  touch WORKSPACE.bzlmod
+  cat > MODULE.bazel <<EOF
+module(name="bazel_skylib_test", repo_name="bazel_skylib")
+bazel_dep(name = "platforms", version = "0.0.10")
+register_toolchains(
+    "//toolchains/unittest:cmd_toolchain",
+    "//toolchains/unittest:bash_toolchain",
+)
+EOF
 
   # Copy relevant skylib sources into the current workspace.
   mkdir -p tests