refactor: move act/model and act/exprparser to actionslib (#1143)

Gitea needs the workflow model and the expression evaluator to parse workflows and to build the task payload this runner consumes, so today it depends on `gitea.com/gitea/runner` just for `act/model` and `act/exprparser`. Both packages now live in `gitea.dev/actionslib` (`pkg/model`, `pkg/exprparser`), the module both sides already share, and this repository consumes them from there.

### Changes

- `act/model` and `act/exprparser` are deleted, all imports point at `gitea.dev/actionslib/pkg/...`.
- New `act/ghcontext` package: the `GithubContext` helpers that need a git checkout on disk (`SetRef`, `SetSha`, `SetRepositoryAndOwner`) are runner only and would drag a git client plus the act context logger into the shared module, so they stay here as functions, with their tests. Only caller is `RunContext.getGithubContext`.
- `act/common.CartesianProduct` moved to the shared model package, `act/model` was its only user.
- `act/model/testdata/container-volumes` moved to `act/runner/testdata/container-volumes`, its only user is `runner_test.go`.
- `internal/pkg/client.UUIDHeader` / `TokenHeader` now alias `pkg/protocol`, so the header names cannot drift apart from Gitea.

### Notes

- No behaviour change intended: the moved files are unchanged apart from the import paths and the split described above.
- `go.mod` depends on the released `gitea.dev/actionslib v0.7.0`, which carries both https://gitea.com/gitea/actionslib/pulls/11 and the `model.UsesHash` port in https://gitea.com/gitea/actionslib/pulls/14 that `main` needs after https://gitea.com/gitea/runner/pulls/1150.
- Verified with `go build ./...`, `go vet ./...` and `go test ./act/... ./internal/...`; the docker based `act/runner` integration tests (`TestRunEvent`, `TestRunMatrixWithUserDefinedInclusions`) fail identically with and without this change in my environment.

Assisted-by: Codet:GPT-5.1-Codex
Reviewed-on: https://gitea.com/gitea/runner/pulls/1143
Reviewed-by: silverwind <[email protected]>

act/common/cartesian.go

@@ -1,60 +0,0 @@
-// Copyright 2026 The Gitea Authors. All rights reserved.
-// Copyright 2020 The nektos/act Authors. All rights reserved.
-// SPDX-License-Identifier: MIT
-
-package common
-
-import "slices"
-
-// CartesianProduct takes map of lists and returns list of unique tuples
-func CartesianProduct(mapOfLists map[string][]any) []map[string]any {
-	listNames := make([]string, 0)
-	lists := make([][]any, 0)
-	for k, v := range mapOfLists {
-		listNames = append(listNames, k)
-		lists = append(lists, v)
-	}
-
-	listCart := cartN(lists...)
-
-	rtn := make([]map[string]any, 0)
-	for _, list := range listCart {
-		vMap := make(map[string]any)
-		for i, v := range list {
-			vMap[listNames[i]] = v
-		}
-		rtn = append(rtn, vMap)
-	}
-	return rtn
-}
-
-func cartN(a ...[]any) [][]any {
-	c := 1
-	for _, a := range a {
-		c *= len(a)
-	}
-	if c == 0 || len(a) == 0 {
-		return nil
-	}
-	p := make([][]any, c)
-	b := make([]any, c*len(a))
-	n := make([]int, len(a))
-	s := 0
-	for i := range p {
-		e := s + len(a)
-		pi := b[s:e]
-		p[i] = pi
-		s = e
-		for j, n := range n {
-			pi[j] = a[j][n]
-		}
-		for j := range slices.Backward(n) {
-			n[j]++
-			if n[j] < len(a[j]) {
-				break
-			}
-			n[j] = 0
-		}
-	}
-	return p
-}

act/common/cartesian_test.go

@@ -1,43 +0,0 @@
-// Copyright 2026 The Gitea Authors. All rights reserved.
-// Copyright 2020 The nektos/act Authors. All rights reserved.
-// SPDX-License-Identifier: MIT
-
-package common
-
-import (
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-)
-
-func TestCartesianProduct(t *testing.T) {
-	assert := assert.New(t)
-	input := map[string][]any{
-		"foo": {1, 2, 3, 4},
-		"bar": {"a", "b", "c"},
-		"baz": {false, true},
-	}
-
-	output := CartesianProduct(input)
-	assert.Len(output, 24)
-
-	for _, v := range output {
-		assert.Len(v, 3)
-
-		assert.Contains(v, "foo")
-		assert.Contains(v, "bar")
-		assert.Contains(v, "baz")
-	}
-
-	input = map[string][]any{
-		"foo": {1, 2, 3, 4},
-		"bar": {},
-		"baz": {false, true},
-	}
-	output = CartesianProduct(input)
-	assert.Empty(output)
-
-	input = map[string][]any{}
-	output = CartesianProduct(input)
-	assert.Empty(output)
-}