ci: remove unused add-kitware-repo action

.github/actions/add-kitware-repo/action.yml

@@ -1,34 +0,0 @@
-# SPDX-FileCopyrightText: 2024 Chris Rizzitello <sithlord48@gmail.com>
-# SPDX-License-Identifier: MIT
-
-name: "Add Kitware repo"
-description: "Add Kitware repo for Debian-like distros"
-
-inputs:
-  distro:
-    description: "Ubuntu codename, Kitware uses: noble, jammy, focal"
-    required: true
-
-runs:
-  using: "composite"
-
-  steps:
-
-    # This mirrors instructions at https://apt.kitware.com
-    - name: Add repo
-      run: |
-          apt update -y -qqq
-          apt install ca-certificates gpg wget -y -qqq
-
-          wget -O - https://apt.kitware.com/keys/kitware-archive-latest.asc 2>/dev/null \
-            | gpg --dearmor - \
-            > /usr/share/keyrings/kitware-archive-keyring.gpg
-
-          echo 'deb [signed-by=/usr/share/keyrings/kitware-archive-keyring.gpg] https://apt.kitware.com/ubuntu/ ${{ inputs.distro }} main' \
-            > /etc/apt/sources.list.d/kitware.list
-            
-          apt update -y -qqq
-      env:
-          # Prevent apt prompting for input.
-          DEBIAN_FRONTEND: noninteractive
-      shell: bash