fix: job container, daemon startup, action cache and exec fixes (#1294)

- Keep `GITHUB_ENV`, `GITHUB_OUTPUT`, `GITHUB_STATE` and `GITHUB_PATH` when a job times out or is cancelled, so post steps still get their state
- Retry the startup Declare while Gitea is unreachable instead of exiting, still failing fast on rejected registrations, auth and misconfiguration
- Reuse a local image when a platform variant such as `linux/arm/v7` is requested instead of pulling again
- Read `PATH` from the created job container so cross-architecture jobs get tool paths for the right architecture
- Extract action copies relative to the act volume so they never cross an image's `/var/run` symlink, which rootless Podman rejects
- Keep the job container's entrypoint when container options set `--entrypoint`, warning instead of appending it to the keep-alive command
- Lock action cache entries across runner processes that share a cache directory
- `exec`: omit `GITHUB_SERVER_URL` and `GITHUB_API_URL` without `--gitea-instance` instead of exporting a bare `https://`, and read owner and repository from any origin remote

Reviewed-on: https://gitea.com/gitea/runner/pulls/1294
Reviewed-by: bircni <[email protected]>
Co-authored-by: silverwind <[email protected]>

act/container/docker_platform_test.go

@@ -61,3 +61,26 @@ func TestParsePlatform(t *testing.T) {
 		})
 	}
 }
+
+func TestPlatformMatches(t *testing.T) {
+	for _, testcase := range []struct {
+		requested, image string
+		want             bool
+	}{
+		{"linux/amd64", "linux/amd64", true},
+		{"linux/amd64/v1", "linux/amd64", true},
+		{"linux/arm64", "linux/amd64", false},
+		{"linux/arm64/v8", "linux/arm64", true},
+		{"linux/arm/v7", "linux/arm/v7", true},
+		{"linux/arm", "linux/arm/v7", true},
+		{"linux/arm/v6", "linux/arm/v7", false},
+		{"linux/arm", "linux/arm/v6", true},
+		{"windows/arm/v7", "linux/arm/v7", false},
+	} {
+		requested, err := parsePlatform(testcase.requested)
+		require.NoError(t, err)
+		image, err := parsePlatform(testcase.image)
+		require.NoError(t, err)
+		assert.Equal(t, testcase.want, platformMatches(requested, image), "%s on %s", testcase.requested, testcase.image)
+	}
+}