docs: drop the deprecated CodeSandbox badge (#1636)

CodeSandbox has been deprecated, so the badge pointed at a dead entry
point. The cloud-IDE alternatives all require an account, while the
existing Launch GeoLibre Web badge already offers a no-install,
no-signup way to try the app.

Author: giswqs

README.md

@@ -7,7 +7,6 @@
 [![image](https://colab.research.google.com/assets/colab-badge.svg)](https://colab.research.google.com/github/opengeos/GeoLibre/blob/main/python/examples/getting-started.ipynb)
 [![image](https://img.shields.io/conda/vn/conda-forge/geolibre.svg)](https://anaconda.org/conda-forge/geolibre)
 [![Conda Recipe](https://img.shields.io/badge/recipe-geolibre-green.svg)](https://github.com/conda-forge/geolibre-feedstock)
-[![Open in CodeSandbox](https://img.shields.io/badge/Open%20in-CodeSandbox-blue?logo=codesandbox)](https://codesandbox.io/p/github/opengeos/geolibre)
 [![Microsoft Store](https://img.shields.io/badge/Microsoft%20Store-GeoLibre-0078D4?logo=windows)](https://apps.microsoft.com/detail/9nwt67rv531x)
 [![Google Play](https://img.shields.io/badge/Google%20Play-GeoLibre-01875F?logo=googleplay&logoColor=white)](https://play.google.com/store/apps/details?id=org.geolibre.app)
 [![AUR version](https://img.shields.io/aur/version/geolibre-bin?logo=archlinux&label=AUR)](https://aur.archlinux.org/packages/geolibre-bin)

docs/getting-started.md

@@ -7,7 +7,6 @@
 [![image](https://colab.research.google.com/assets/colab-badge.svg)](https://colab.research.google.com/github/opengeos/GeoLibre/blob/main/python/examples/getting-started.ipynb)
 [![image](https://img.shields.io/conda/vn/conda-forge/geolibre.svg)](https://anaconda.org/conda-forge/geolibre)
 [![Conda Recipe](https://img.shields.io/badge/recipe-geolibre-green.svg)](https://github.com/conda-forge/geolibre-feedstock)
-[![Open in CodeSandbox](https://img.shields.io/badge/Open%20in-CodeSandbox-blue?logo=codesandbox)](https://codesandbox.io/p/github/opengeos/geolibre)
 [![Microsoft Store](https://img.shields.io/badge/Microsoft%20Store-GeoLibre-0078D4?logo=windows)](https://apps.microsoft.com/detail/9nwt67rv531x)
 [![Google Play](https://img.shields.io/badge/Google%20Play-GeoLibre-01875F?logo=googleplay&logoColor=white)](https://play.google.com/store/apps/details?id=org.geolibre.app)
 [![AUR version](https://img.shields.io/aur/version/geolibre-bin?logo=archlinux&label=AUR)](https://aur.archlinux.org/packages/geolibre-bin)