text: Title: `micromamba` initialize block causes `micromamba` completions to show up for all executables
  Body: ## Current Behavior
  <!---
  For general xonsh issues, please try to replicate the failure using `xonsh --no-rc --no-env`.
  Short, reproducible code snippets are highly appreciated.
  You can use `$XONSH_SHOW_TRACEBACK=1`, `$XONSH_TRACE_SUBPROC=2`, or `$XONSH_DEBUG=1`
  to collect more information about the failure.
  -->
  After installing [micromamba through the recommended pathway](https://mamba.readthedocs.io/en/latest/installation/micromamba-installation.html#automatic-install), and initializing for `xonsh` with `micromamba shell init`, the following lines are added to my `.xonshrc`:
  
  ```xsh
  # >>> mamba initialize >>>
  # !! Contents within this block are managed by 'mamba init' !!
  $MAMBA_EXE = "/home/david/.local/bin/micromamba"
  $MAMBA_ROOT_PREFIX = "/home/david/micromamba"
  import sys as _sys
  from types import ModuleType as _ModuleType
  _mod = _ModuleType("xontrib.mamba",
                     'Autogenerated from $($MAMBA_EXE shell hook -s xonsh -p $MAMBA_ROOT_PREFIX)')
  __xonsh__.execer.exec($($MAMBA_EXE shell hook -s xonsh -p $MAMBA_ROOT_PREFIX),
                        glbs=_mod.__dict__,
                        filename='$($MAMBA_EXE shell hook -s xonsh -p $MAMBA_ROOT_PREFIX)')
  _sys.modules["xontrib.mamba"] = _mod
  del _sys, _mod, _ModuleType
  # <<< mamba initialize <<<
  ```
  
  Starting a new shell instance, typing `micromamba ` and hitting `<TAB>` yields:
  
  ![image](https://github.com/user-attachments/assets/090936b1-8a17-4ce3-97bf-efd02fffdabc)
  
  but doing the same for another executable, e.g. `rsync` or `vim`, also yields these:
  
  ![image](https://github.com/user-attachments/assets/f9e1138e-7590-4f26-9c18-f58d8b40b0a9)
  
  However, ensuring that the `micromamba` executable isn't in `$PATH` removes these completions, including from `micromamba` usage:
  
  ```xsh
  $PATH.pop('/home/david/.local/bin')
  ```
  
  and using e.g. `micromamba activate` still works.
  
  
  
  Traceback (if applicable):
  
  <details>
  
  ```xsh
  # Please paste the traceback here.
  ```
  
  </details>
  
  ## Expected Behavior
  <!--- What you expect and what is your real life use case. -->
  
  I would expect that if `micromamba` completions show up at all, they show up only for `micromamba`, not for any and all executables. Any ideas as to what could be happening here?
  
  ## xonfig
  
  <details>
  
  ```xsh
  +-----------------------------+----------------------+
  | xonsh                       | 0.17.0               |
  | Python                      | 3.12.4               |
  | PLY                         | 3.11                 |
  | have readline               | True                 |
  | prompt toolkit              | 3.0.47               |
  | shell type                  | prompt_toolkit       |
  | history backend             | sqlite               |
  | pygments                    | 2.18.0               |
  | on posix                    | True                 |
  | on linux                    | True                 |
  | distro                      | arch                 |
  | on wsl                      | False                |
  | on darwin                   | False                |
  | on windows                  | False                |
  | on cygwin                   | False                |
  | on msys2                    | False                |
  | is superuser                | False                |
  | default encoding            | utf-8                |
  | xonsh encoding              | utf-8                |
  | encoding errors             | surrogateescape      |
  | xontrib 1                   | vox                  |
  | xontrib 2                   | voxapi               |
  | RC file 1                   | /home/david/.xonshrc |
  | UPDATE_OS_ENVIRON           | False                |
  | XONSH_CAPTURE_ALWAYS        | False                |
  | XONSH_SUBPROC_OUTPUT_FORMAT | stream_lines         |
  | THREAD_SUBPROCS             | True                 |
  | XONSH_CACHE_SCRIPTS         | True                 |
  +-----------------------------+----------------------+
  ```
  
  
  </details>
  
  ## For community
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