meta: add workflow perms; fix broken workflows

Signed-off-by: NotAShelf <raf@notashelf.dev>
Change-Id: I6a6a6964ea7f970a8a9040ca994bfe6aabecb408

.github/workflows/nix-cache.yaml

@@ -1,19 +1,28 @@
 name: "Populate cachix cache"
+
 on:
   workflow_dispatch:
   push:
-    branches: [ master ]
+    branches: [ "main" ]
     paths: [ 'src/**.rs', 'Cargo.toml', 'Cargo.lock', 'nix/package.nix' ]
+
+permissions:
+  contents: read
+
 jobs:
   populate-cache:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
-    - uses: cachix/install-nix-action@v25
-      with:
-        nix_path: nixpkgs=channel:nixos-unstable
-    - uses: cachix/cachix-action@v14
-      with:
-        name: nyx
-        authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
-    - run: nix build
+      - name: "CHeckout"
+        uses: actions/checkout@v4
+
+      - uses: cachix/install-nix-action@v25
+        with:
+          nix_path: nixpkgs=channel:nixos-unstable
+
+      - uses: cachix/cachix-action@v14
+        with:
+          name: nyx
+          authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
+
+      - run: nix build