Inconsistent `pull_policy` behavior with `docker compose` when combining build and image

https://docs.docker.com/reference/compose-file/build/#using-build-and-image

https://docs.docker.com/reference/compose-file/services/#image

> [Using build and image](https://docs.docker.com/reference/compose-file/build/#using-build-and-image)
When Compose is confronted with both a build subsection for a service and an image attribute, it follows the rules defined by the [pull_policy](https://docs.docker.com/reference/compose-file/services/#pull_policy) attribute.
>
> If pull_policy is missing from the service definition, Compose attempts to pull the image first and then builds from source if the image isn't found in the registry or platform cache.

i.e. by default it should pull `image` from registry/cache before attempting to build when using `docker compose up`, therefore I expect

```diff
.devcontainer/devcontainer.json --- JSON
1
2 {
3 "name": "Repro",
4 "dockerComposeFile": "../compose.yml",
5 "service": "devcontainer",
6 "workspaceFolder": ".",
7 "runServices": [
8 "db"
9 ]
10 }
11

compose.yml --- YAML
1 services:
2 devcontainer:
3 image: mcr.microsoft.com/devcontainers/base:ubuntu
4 volumes:
5 - ../..:/workspaces:cached
6 network_mode: service:db
7 command: sleep infinity
8
9 db:
10 image: postgres:latest
11 build:
12 context: .
13 dockerfile_inline: |
14 FROM postgres:latest
15 restart: unless-stopped
16 volumes:
17 - postgres-data:/var/lib/postgresql/data
18 environment:
19 POSTGRES_PASSWORD: postgres
20 POSTGRES_USER: postgres
21 POSTGRES_DB: postgres
22
23 volumes:
24 postgres-data:
25

```
(output from `git diff`)

to *not* run `docker compose build db` when running `@devcontainers/cli up --workspace-folder .`

But it currently runs `docker compose --project-name devcontainer-repro -f /devcontainer-repro/compose.yml build db devcontainer`

Why this matters:

When trying to prebuild/cache images it is beneficial to have one `compose.yml` which both defines the image and how to build the image, otherwise you need to split the file in two `compose.build.yml` and `compose.yml`. This behavior is inconsistent and confusing.

使用 .devcontainer/devcontainer.json 和 compose.yml，通过 @devcontainers/cli up --workspace-folder .. 重现该行为。首先跟踪此入口点如何处理同时定义 image 和 build 的服务，然后将生成的 docker compose 命令与文档中说明的 pull_policy 行为进行比较。当应当拉取镜像或从缓存中找到镜像时，默认工作流不会对 db 运行 docker compose build，即表示完成。

由索引模型根据 Issue 内容生成。