bug: Completion of set command uses all available versions not just the installed ones

### Describe the Bug

The (zsh) completion of the `set` subcommand uses the `asdf list all "$plugin"` command to list the available versions to set. The problem is that `asdf list all "$plugin"` lists all the available versions (to install), not only the installed ones. This makes the completion of `set` useless since that subcommand should only need to browse the installed versions.

For example, let's say you use the `java` plugin, and you have three Java versions installed. When you use `asdf set java`, you will get 1948 options as of today not three:
```sh
asdf list all java | wc -l
1948
```

See
https://github.com/asdf-vm/asdf/blob/2114f1ebc15b3f1653228c8b416f759898a58dc7/internal/completions/asdf.zsh#L314
and
https://github.com/asdf-vm/asdf/blob/2114f1ebc15b3f1653228c8b416f759898a58dc7/internal/completions/asdf.zsh#L329

### Steps to Reproduce

`asdf set `

### Expected Behaviour

Listing the installed versions, the output of `asdf list "$plugin"` instead of `asdf list all "$plugin"`.

### Actual Behaviour

Listing every version available, not only the versions that are installed.

### Environment

```shell
❯ asdf info
OS:
Darwin 24.5.0 Darwin Kernel Version 24.5.0: Tue Apr 22 19:54:43 PDT 2025; root:xnu-11417.121.6~2/RELEASE_ARM64_T8132 arm64

SHELL:
zsh 5.9 (arm64-apple-darwin24.0)

BASH VERSION:
5.2.37(1)-release

ASDF VERSION:
0.18.0 (revision unknown)

ASDF INTERNAL VARIABLES:
ASDF_TOOL_VERSIONS_FILENAME=.tool-versions
ASDF_DATA_DIR=/Users//.asdf
ASDF_CONFIG_FILE=/Users//.asdfrc

ASDF INSTALLED PLUGINS:
java https://github.com/halcyon/asdf-java.git
e18c5fcf11d990392abd59a71faa299e8b2e9a21
nodejs https://github.com/asdf-vm/asdf-nodejs.git
fd2c7f94c4c71416047cacf2af6e4fa819b364b7
```

### asdf plugins affected (if relevant)

all

See: https://github.com/asdf-vm/asdf/pull/2022

Start in internal/completions/asdf.zsh at the completion logic around lines 314 and 329. Compare the version source used by the set subcommand with the installed-version command described in the issue, then reproduce asdf set and confirm that only installed versions are listed.

Written by the indexing model from the issue text.