Feature Request: New Format `pkgname-no-coverage` to Suppress Coverage Reporting

# Feature Request: New Format `pkgname-no-coverage` to Suppress Coverage Reporting

**Context**

When using the `pkgname` format with `go test` coverage flags, coverage is reported inline in test results:

```
✓ test/pkg/foo (coverage: 91.2% of statements in ./pkg/...)
```

## Problem

This reported coverage figure does not respect user-defined coverage semantics when tools or libraries are used to manipulate coverage data, for example, adding ignore directives to exclude specific code branches.

## Proposed Solution

Introduce a new format option `pkgname-no-coverage` that behaves identically to `pkgname` but suppresses the coverage line from test output.

---

I am willing to open a PR implementing this if maintainers consider it a valid addition.

Start by locating the existing `pkgname` format handling and its tests, then trace how `go test` coverage flags reach the formatted output. Add the `pkgname-no-coverage` option with the same behavior as `pkgname` except for the coverage line, and verify both formats' output.

Written by the indexing model from the issue text.