build: replace deprecated "dependency-check" with knip

depdendency-check started to fail with an error that does not even include
a stack trace.

knip does a little bit more than dependency-check did. We disable some of
the rules because they just generate noise for now.

A note about the knip.json: every file suffixed by "!" is one that is used
in prod mode (npm run knip:prod).

build.sh

@@ -4,4 +4,6 @@ rimraf dist
 tsc --skipLibCheck
 cpy --flat src/schema/preparation/source-validation-modules/schema dist/src/schema/preparation/source-validation-modules/schema
 node ./emit-cruddl-version.js
-dependency-check ./package.json --no-dev --ignore-module @arangodb --ignore-module internal
+# check e.g. for imports from modules that are not listed as dependencies
+npm run knip
+npm run knip:prod

knip.json

@@ -0,0 +1,13 @@
+{
+  "$schema": "https://unpkg.com/knip@5/schema.json",
+  "entry": ["index.ts!", "spec/**/*.spec.ts", "src/project/project-from-fs.ts!"],
+  "project": ["src/**/*.ts!", "spec/**/*.ts"],
+  "rules": {
+    "exports": "off",
+    "types": "off",
+    "enumMembers": "off",
+    "duplicates": "off"
+  },
+  "ignoreDependencies": ["@arangodb", "internal", "tslib"],
+  "ignoreBinaries": ["arangodb"]
+}