bug: ionic-cli installs capacitor regardless

This is probably the same bug as reported in ionic-team/ionic-framework#22366 but the bug reporter might not have explained in a good way what happens.

# Bug Report

**Ionic version:**
```
$ ionic -v
6.12.1
```

**Current behavior:**
```
$ ionic start frontend sidemenu --type vue
[INFO] Existing git project found (/repo). Git operations are disabled.
✔ Preparing directory ./frontend in 11.56ms
✔ Downloading and extracting sidemenu starter in 870.79ms
> ionic integrations enable capacitor --quiet -- frontend io.ionic.starter
> npm i --save -E @capacitor/core
```

**Expected behavior:**
No mention of
```
> ionic integrations enable capacitor --quiet -- frontend io.ionic.starter
> npm i --save -E @capacitor/core
```

**Other information:**
The reason for our distress is that capacitor is marked as `(experimental)` in the CLI help output. There is also no way of explicitly disable it. It can be enabled with `--capacitor` which of course should mean that the default (if omitted) should be disabled. But that is not what is being observed, and with no way of forcing the desired result.

**Ionic info:**
```
$ ionic info
[WARN] You are not in an Ionic project directory. Project context may be missing.

Ionic:
Ionic CLI : 6.12.1

Utility:
cordova-res : not installed
native-run : not installed

System:
NodeJS : v12.19.0
npm : 6.14.8
OS : Linux 4.19
```