Fix missing rimraf dependency in @storage-explorer/testing

[craxal]

Problem

@storage-explorer/testing's RandomUtils.js requires rimraf but doesn't declare it as a dependency. This causes MODULE_NOT_FOUND errors at test time for consumers like queue-extension.

Suggested Fix

Either:

1. Remove the rimraf dependency — replace rimraf usage in RandomUtils with fs.rm(path, { recursive: true }) (Node 14.14+), which eliminates the external dep entirely.
2. Declare the dependency — add rimraf to @storage-explorer/testing's package.json dependencies.

Option 1 is preferred since Node's built-in fs.rm is sufficient and reduces the dependency footprint.

Files Affected

• src/components/testing/src/RandomUtils.ts (only file using rimraf)