Close legacy branches

[mhubii]

Remove legacy branches, such as

• https://github.com/lbr-stack/fri/tree/dev-eld
• These might require changes to https://github.com/lbr-stack/lbr_fri_ros2_stack
  • https://github.com/lbr-stack/fri/tree/ros
  • https://github.com/lbr-stack/fri/tree/ros2-fri-1.15
  • https://github.com/lbr-stack/fri/tree/ros2-fri-2.5

These are nowadays fetched at compile time via fri_vendor https://github.com/lbr-stack/fri_vendor