Remove k6pack dependency in favor of k6's native TypeScript support

[jalevin]

Background

github.com/grafana/k6pack (previously github.com/szkiba/k6pack) is now archived (October 2025). It was a TypeScript transpiler/bundler for k6, but its functionality has been superseded by k6's built-in esbuild pipeline introduced in k6 v1.4.0.

Since we use grafana/k6:latest (currently v1.6.x), k6 can now run .ts files directly via k6 run script.ts without any external transpilation step.

What needs to change

In pkg/executor/k6/k6_executor.go:

• Remove the transpileTest() function (lines ~298-325) which calls k6pack.Pack() to transpile TypeScript to a temp JS file
• In execTest(), remove the transpileTest() call and pass testFile directly to prepareK6Command()
• Remove the "github.com/szkiba/k6pack" import

In go.mod / go.sum:

• Remove github.com/szkiba/k6pack

Why now

PR #836 (Renovate) attempted to bump k6pack from v0.1.3 → v0.2.4, but v0.2.4 renamed the module path to github.com/grafana/k6pack and the package is archived with no future updates. We patched it with option 2 (import path update) as a short-term fix, but the right long-term solution is to remove the dependency entirely.

Acceptance criteria

• transpileTest() removed from k6_executor.go
• k6pack removed from go.mod / go.sum
• CI k6 tests pass (k6 handles .ts files natively)
• PR fix(deps): update module github.com/szkiba/k6pack to v0.2.4 #836 can be closed