Bug Fix

The CGO run #4767 failed in the fuzz matrix due to FuzzWrapExpressionsInTemplateConditionals flagging malformed elseif fragments as canonicalization failures. This change narrows the fuzz invariant so malformed brace structures are treated as malformed input, not product regressions.

• ### What was the bug?

  • The fuzz assertion treated inputs like {{#if{{elseif {}} as non-canonical elseif output, even though the fragment is malformed and not a valid canonicalization target.

• ### How did you fix it?

  • Added the CI-reproduced malformed seed to the fuzz corpus:
    • {{#if{{elseif {}}
  • Refined the elseif canonicalization assertion guard in pkg/workflow/template_fuzz_test.go to skip malformed fragments when:
    • nested/double braces are present ({{ / }})
    • brace counts are unbalanced ({ count != } count)
  • Documented the guard as a fuzz-specific malformed-input heuristic.

• ### Example

if hasSkippableElseifExprPrefix(expr) ||
	strings.Contains(expr, "{{") ||
	strings.Contains(expr, "}}") ||
	strings.Count(expr, "{") != strings.Count(expr, "}") {
	continue
}