build: add tsconfig with strict flag to dev-infra package (#38656)

The dev-infra package is currently built with Bazel and ts-node.
In Bazel, the shared tsconfig from the `packages/` folder is used.

This means that the code is built in strict mode, but IDEs and
ts-node do not know about the strictness. This is because the tsconfig
is part of the `packages` folder and not accessible from the
dev-infra package. We fix this by adding an IDE and ts-node specific
tsconfig to the dev-infra package.

This helps with spotting compilation failures before building
with Bazel / waiting for CI to check build state.

PR Close #38656

dev-infra/tsconfig.json

@@ -0,0 +1,5 @@
+{
+  "compilerOptions": {
+    "strict": true
+  }
+}