chore(affinescriptiser): delete unfilled flake.nix scaffold leftover

The file had {{PROJECT_NAME}}, {{CURRENT_YEAR}}, {{AUTHOR}}, etc.
placeholders throughout — never instantiated from the project-scaffold
template. As-is it isn't a usable Nix flake (nix can't parse the
placeholders).

Not referenced by any tool: `grep -rln "affinescriptiser/flake"`
across .sh / .yml / .adoc / .md / .toml / .just returns empty. No
parent flake.nix at the affinescript root either (this is an OCaml +
AffineScript primary repo; Nix is fallback only at the sub-package
level, and the parent has guix.scm as the primary dev env).

Deleting honestly disposes of the unfilled template rather than
suppressing the panic-attack SupplyChain finding (unpinned inputs)
which is technically correct but moot for an un-parseable file. If
affinescriptiser ever needs a real flake.nix later, instantiate from
a fresh template with real values + input pinning + flake.lock.

This is the third commit of the #378 triage (one suppression file +
this delete; the other 8 findings are FPs covered in the suppression
file).

Refs #378

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: hyperpolymath