Fix Go linting errors in known_needs_expressions_test.go

[Copilot]

CI lint step failing with 3 violations in pkg/workflow/known_needs_expressions_test.go:

• staticcheck SA4006: unused promptSection variable assignment
• testifylint negative-positive: two instances of require.Greater(t, x, 0) flagged

Changes

• Replace require.Greater(t, x, 0) with require.Positive(t, x) for idiomatic positive value assertions
• Remove unused promptSection calculation, replace with blank identifier _ and explanatory comment

// Before
require.Greater(t, substStepStart, 0, "Substitution step not found")
promptSection := lockStr[promptStepStart:]
nextStepIdx = strings.Index(promptSection[50:], "- name:")
if nextStepIdx > 0 {
    promptSection = promptSection[:50+nextStepIdx]
}

// After  
require.Positive(t, substStepStart, "Substitution step not found")
_ = lockStr[promptStepStart:]  // Reserved for potential future checks

Original prompt

Reference: https://github.com/github/gh-aw/actions/runs/22087569443/job/63825848554#step:7:1

Lint go

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[Copilot]

Pull request overview

This PR fixes three Go linting violations in pkg/workflow/known_needs_expressions_test.go identified by the CI lint step: two testifylint negative-positive violations and one staticcheck SA4006 unused variable violation.

Changes:

• Replaced require.Greater(t, x, 0) with require.Positive(t, x) for idiomatic positive value assertions (testifylint compliance)
• Removed unused promptSection variable assignment (staticcheck SA4006 fix)

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[Copilot]

Computing a value just to assign it to the blank identifier is unnecessary and wasteful. If this section extraction is not being used for any assertions, both the comment and the computation should be removed entirely. The test already verifies the prompt step exists via the require.Positive check at line 522 and the assert.Contains check at line 530.

Suggested change

	// Get the prompt creation section (not currently used but kept for potential future checks)
	_ = lockStr[promptStepStart:]