chore: remove obsolete gitpod integration (#13334)

.gitpod.Dockerfile

@@ -1,5 +0,0 @@
-FROM gitpod/workspace-full
-
-RUN sudo apt-get update && \
-    sudo apt-get install -y zsh && \
-    sudo rm -rf /var/lib/apt/lists/*

.gitpod.yml

@@ -1,9 +0,0 @@
-image:
-  file: .gitpod.Dockerfile
-
-tasks:
-  - init: |
-      export EDITOR="command gp open -w" VISUAL="command gp open -w"
-      cp -f /workspace/ohmyzsh/templates/zshrc.zsh-template ~/.zshrc
-      ln -sf /workspace/ohmyzsh ~/.oh-my-zsh
-    command: exec zsh

README.md

@@ -21,7 +21,6 @@ Twitter), and join us on [Discord](https://discord.gg/ohmyzsh).
 [![X (formerly Twitter) Follow](https://img.shields.io/twitter/follow/ohmyzsh?label=%40ohmyzsh&logo=x&style=flat)](https://twitter.com/intent/follow?screen_name=ohmyzsh)
 [![Mastodon Follow](https://img.shields.io/mastodon/follow/111169632522566717?label=%40ohmyzsh&domain=https%3A%2F%2Fmstdn.social&logo=mastodon&style=flat)](https://mstdn.social/@ohmyzsh)
 [![Discord server](https://img.shields.io/discord/642496866407284746)](https://discord.gg/ohmyzsh)
-[![Gitpod ready](https://img.shields.io/badge/Gitpod-ready-blue?logo=gitpod)](https://gitpod.io/#https://github.com/ohmyzsh/ohmyzsh)
 
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 <summary>Table of Contents</summary>