ci: disable detsys telemetry, use our binary cache URL as upstream

Signed-off-by: strawberry <strawberry@puppygock.gay>

.github/workflows/ci.yml

@@ -73,6 +73,9 @@ jobs:
 
             - name: Configure Magic Nix Cache
               uses: DeterminateSystems/magic-nix-cache-action@main
+              with:
+                diagnostic-endpoint: ""
+                upstream-cache: "https://attic.kennel.juneis.dog"
 
             - name: Apply Nix binary cache configuration
               run: |

.github/workflows/documentation.yml

@@ -73,6 +73,9 @@ jobs:
 
       - name: Pop/push Magic Nix Cache
         uses: DeterminateSystems/magic-nix-cache-action@main
+        with:
+          diagnostic-endpoint: ""
+          upstream-cache: "https://attic.kennel.juneis.dog"
 
       - name: Configure `nix-direnv`
         run: |