fix: avoid 'filename too long' on matrix jobs by hashing container names (#853)

## Bug fixes

- Fixed "file name too long" errors when running matrix jobs with many or
  long-valued matrix parameters. Docker volume and container names are now
  bounded to a safe length by hashing the full name with SHA-256, keeping
  the result well within the filesystem `NAME_MAX` limit (255 bytes) even
  after Docker appends its own suffixes (`-env`, `-network`, etc.).

## Upgrade notes

This change renames the Docker containers, volumes and networks created by
the runner. Resources created by a previous version will **not** be cleaned
up automatically after upgrade and will become orphans.

After upgrading, you can remove the legacy resources with:

```sh
# volumes
docker volume ls -q | grep -E '^GITEA-ACTIONS-TASK-[0-9]+_' | xargs -r docker volume rm

# networks
docker network ls --format '{{.Name}}' | grep -E '^GITEA-ACTIONS-TASK-[0-9]+_.*-network$' | xargs -r docker network rm
```

> **Note:** If multiple act_runner instances share the same Docker daemon,
> make sure no runner using the old version is running before executing the
> cleanup commands above.

Fixes #686

---------

Co-authored-by: Nicolas <bircni@icloud.com>
Reviewed-on: https://gitea.com/gitea/act_runner/pulls/853
Reviewed-by: silverwind <2021+silverwind@noreply.gitea.com>
Co-authored-by: Morgan Peyre <195218+peyremorgan@noreply.gitea.com>
Co-committed-by: Morgan Peyre <195218+peyremorgan@noreply.gitea.com>

act/runner/run_context_test.go

@@ -622,23 +622,16 @@ func TestRunContextGetEnv(t *testing.T) {
 	}
 }
 
-func Test_createSimpleContainerName(t *testing.T) {
-	tests := []struct {
-		parts []string
-		want  string
-	}{
-		{
-			parts: []string{"a--a", "BB正", "c-C"},
-			want:  "a-a_BB_c-C",
-		},
-		{
-			parts: []string{"a-a", "", "-"},
-			want:  "a-a",
-		},
-	}
-	for _, tt := range tests {
-		t.Run(strings.Join(tt.parts, " "), func(t *testing.T) {
-			assert.Equalf(t, tt.want, createSimpleContainerName(tt.parts...), "createSimpleContainerName(%v)", tt.parts)
-		})
-	}
+func TestCreateContainerNameBoundedForLongMatrixInput(t *testing.T) {
+	longMatrixValue := strings.Repeat("os=ubuntu-latest-go=1.24-node=22-", 20)
+	name := createContainerName(
+		"gitea",
+		"WORKFLOW-super-long-workflow-name",
+		"JOB-build-matrix-"+longMatrixValue,
+	)
+
+	assert.LessOrEqual(t, len(name), 128)
+	assert.LessOrEqual(t, len(name+"-env"), 255)
+	assert.LessOrEqual(t, len(name+"-network"), 255)
+	assert.LessOrEqual(t, len(name+"-job1234567890"), 255)
 }