build: optimise pipeline runs (#7)

Reviewed-on: https://git.vdx.hu/voidcontext/woodpecker-plugin-nix-attic/pulls/7
Co-authored-by: Gabor Pihaj <gabor.pihaj@gmail.com>
Co-committed-by: Gabor Pihaj <gabor.pihaj@gmail.com>

.woodpecker/ci.yaml

@@ -5,11 +5,17 @@ variables:
       binary_cache_token:
         from_secret: attic_token
 
+when:
+  - event: pull_request
+  - event: push
+    branch: main
+
 steps:
   build:
     when:
-      - event: push
       - event: pull_request
+      - event: push
+        branch: main
     image: git.vdx.hu/voidcontext/woodpecker-plugin-nix-attic
     settings:
       <<: *common_settings

.woodpecker/release.yaml

@@ -1,4 +1,3 @@
-
 variables:
   - common_settings: &common_settings
       binary_cache: https://cache.nix.vdx.hu/private
@@ -6,10 +5,11 @@ variables:
       binary_cache_token:
         from_secret: attic_token
 
+when:
+  - event: tag
+  
 steps:
   release:
-    when:
-      - event: tag
     image: git.vdx.hu/voidcontext/woodpecker-plugin-nix-attic
     settings:
       <<: *common_settings