ESS layer does not bind keys for inferior-ess-mode

[NicholasKirchner]

Description

ESS layer key combinations don't work from R repl.

Reproduction guide 🪲

• Start Emacs
• Load a .R file to activate ess layer
• SPC m ' to start an R repl
• From repl buffer, try SPC m s s

Observed behaviour: 👀 💔
Nothing happens. inferior-ess-mode does not get the key bindings that it's supposed to.

Expected behaviour: ❤️ 😄
Focus should switch back to the .R file, because SPC m s s is supposed to be bound to ess-switch-to-inferior-or-script-buffer.

System Info 💻

• OS: darwin
• Emacs: 29.2
• Spacemacs: 0.999.0
• Spacemacs branch: develop (rev. 8f70193)
• Graphic display: t
• Running in daemon: nil
• Distribution: spacemacs
• Editing style: vim
• Completion: helm
• Layers:

(ruby yaml
      (lsp :variables lsp-ui-doc-enable nil lsp-lens-enable nil)
      (javascript :variables javascript-backend 'lsp js2-mode-show-strict-warnings nil js2-mode-show-parse-errors nil)
      (elixir :variables elixir-backend 'lsp elixir-ls-path "~/bin/elixir-ls-v0.17.10/")
      (docker :variables docker-dockerfile-backend 'lsp)
      (go :variables go-tab-width 4 go-backend 'lsp)
      (ess :variables ess-r-backend 'lsp)
      clojure ruby-on-rails html latex themes-megapack theming git finance emacs-lisp helm multiple-cursors
      (shell :variables set-default-shell 'vterm shell-default-height 30 shell-default-position 'bottom)
      spell-checking version-control treemacs)

• System configuration features: ACL DBUS GLIB GNUTLS JSON LCMS2 LIBXML2 MODULES NATIVE_COMP NOTIFY KQUEUE NS PDUMPER PNG RSVG SQLITE3 THREADS TOOLKIT_SCROLL_BARS TREE_SITTER WEBP XIM XWIDGETS ZLIB

[NicholasKirchner]

Proposed PR: #16310