chore(assertions): fix build for nozem 0.11.0 (aws#15251)

----

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packages/@aws-cdk/assertions/package.json

@@ -59,6 +59,7 @@
   "devDependencies": {
     "@types/jest": "^26.0.23",
     "cdk-build-tools": "0.0.0",
+    "@aws-cdk/cfnspec": "0.0.0",
     "constructs": "^3.3.69",
     "jest": "^26.6.3",
     "pkglint": "0.0.0",
@@ -102,6 +103,15 @@
   "engines": {
     "node": ">= 10.13.0 <13 || >=13.7.0"
   },
+  "nozem": {
+    "ostools": ["dirname", "cd", "bash", "rm", "xargs", "sed", "mkdir", "rsync", "cat", "find"],
+    "additionalDirs": [
+      "../cfnspec/lib",
+      "ARTIFACTS:../cfnspec/spec",
+      "../cloudformation-diff",
+      "../assert-internal"
+    ]
+  },
   "stability": "experimental",
   "maturity": "experimental",
   "publishConfig": {