Updates in preparation for release

Unbreak go generate

stack: Fix test expectations for go1.19 and update GA to go1.19

Bump github actions to run on go1.19.

When starting a program on macOS on go1.18 and earlier, it seems that
exec.Cmd.Run() used to evaluate symlinks. It is not true anymore on
go1.19. Update test expectations accordingly.

go1.19 also changed stack traces to not include assembly like it did
previously.

Test only change.

stack: skip TestAugment/18-float64 on arm and mipsle

Fixes #80

Avoid unicode filename (#78)

This is similar to 53e9d3e.

Over at https://github.com/cockroachdb/cockroach, we use bazel and it
chokes on this file:

```
java.io.IOException: Error extracting
[...]/com_github_maruel_panicparse_v2-v2.2.1.zip to [...]:
[...]/com_github_maruel_panicparse_v2/cmd/panic/internal/utf8/?tf8.go
(Illegal byte sequence)
```

which is why we're on a fork so far. It would be nice to avoid this.

There is an (eternal, it seems) [upstream discussion], so there is
little home of bazel starting to support non-unicode filenames.

[upstream discussion]: bazelbuild/bazel#374

README.md: remove EOL whitespace

No functional change

v1: add banner to warn when using the wrong version

github actions: increase timeout to 60s

It's due to macOS GitHub Actions workers that are very underpowered.

stack: Fix a parsing bug when code location is not detected

Add test case that reproduces bug and confirm it's fixed.

Improve another test expectation in stack_test.go.

Fixes #56

vendored v2 stack: Fix a parsing bug when code location is not detected

Bump the vendored and go.mod v2 stack to v2.1.1 to ensure the fix for
issue 56 is in.