Move scripts/flake-regressions.sh into the flake-regressions repo

It already contained a script "eval-all.sh" that did almost the same thing.

.github/workflows/ci.yml

@@ -214,4 +214,4 @@ jobs:
           path: flake-regressions/tests
       - uses: DeterminateSystems/nix-installer-action@main
       - uses: DeterminateSystems/magic-nix-cache-action@main
-      - run: nix build --out-link ./new-nix && PATH=$(pwd)/new-nix/bin:$PATH scripts/flake-regressions.sh
+      - run: nix build --out-link ./new-nix && PATH=$(pwd)/new-nix/bin:$PATH MAX_FLAKES=25 flake-regressions/eval-all.sh

scripts/flake-regressions.sh

@@ -1,27 +0,0 @@
-#! /usr/bin/env bash
-
-set -e
-
-echo "Nix version:"
-nix --version
-
-cd flake-regressions
-
-status=0
-
-flakes=$(find tests -mindepth 3 -maxdepth 3 -type d -not -path '*/.*' | sort | head -n25)
-
-echo "Running flake tests..."
-
-for flake in $flakes; do
-
-    if ! REGENERATE=0 ./eval-flake.sh "$flake"; then
-        status=1
-        echo "❌ $flake"
-    else
-        echo "✅ $flake"
-    fi
-
-done
-
-exit "$status"