test: migrate `.profiled` callers to sibling cabal.project
v2 slices no longer ship `.profiled` as an overlay rebuild — see
`docs/dev/profiling.md`. Migrate the remaining tests that
referenced `…components.<kind>.<name>.profiled`
(`js-template-haskell`, `th-dlls-minimal`, `gi-gtk`) to a sibling
project whose `cabalProjectLocal` enables profiling, matching the
shape already used by `exe-dlls` / `exe-lib-dlls` / `th-dlls`.
Expose each new project's `plan-nix` under a distinct
`ifdInputs` key so the materialised plan-nix expressions are
covered by CI:
plan-nix — non-profiled (default)
plan-nix-ei — externalInterpreter variant (th-dlls /
th-dlls-minimal)
plan-nix-profiled — profiled
plan-nix-profiled-ei — profiled + externalInterpreter