If you’re using Linux x86_64, you can get the binaries already linked from here: GitHub - mgrojo/emacs-ada-mode-binaries: AppImages of the Emacs ada-mode executables, or you can take a look at how they are linked there in the GitHub action: emacs-ada-mode-binaries/.github/workflows/main.yml at a1bdd586ab3417d286bdcd07d3c2fc4f94d985d5 · mgrojo/emacs-ada-mode-binaries · GitHub
There are also alternatives to ada-mode, as GitHub - brownts/ada-ts-mode: Ada major mode using tree-sitter for Emacs and a distribution of ada-ts-mode for Doom Emacs: GitHub - tomekw/doom-ada: Doom Emacs Ada language module with syntax highlighting, LSP and Alire support
Finally, if you don’t mind reading a lot, you have useful information in this other topic: Getting Emacs ada-mode working