env vars can be read in aio app dev creating confusion

### Expected Behaviour

dev command mimics runtime env

### Actual Behaviour

action code that references process.env can see the env used to run the app, there is no indication that this is not expected behavior so if this is discovered and used the app will break when deployed to Runtime.
In some cases the value of .env will be built right into the action as webpack thinks it is doing us a favor.

We need to do a couple things potentially:
- make aio app dev use a clean env when running actions
- prevent devs from accidentally building secrets into their action code

### Reproduce Scenario (including but not limited to)

#### Steps to Reproduce

#### Environment Info
```
System:
OS: macOS 15.4.1
CPU: (10) arm64 Apple M1 Max
Memory: 221.25 MB / 32.00 GB
Shell: 5.9 - /bin/zsh
Binaries:
Node: 18.20.4 - ~/.nvm/versions/node/v18.20.4/bin/node
Yarn: 1.22.19 - ~/.bun/bin/yarn
npm: 10.7.0 - ~/.nvm/versions/node/v18.20.4/bin/npm
Virtualization:
Docker: 20.10.17 - /usr/local/bin/docker
npmGlobalPackages:
@adobe/aio-cli: 10.3.1
```
#### Sample Code that illustrates the problem

#### Logs taken while reproducing problem