.tangled/workflows: run CI on branch-based PRs

Signed-off-by: oppiliappan <[e-mail]>

.tangled/workflows/build.yml

···
 when:
-  - event: ["push"]
+  - event: ["push", "pull_request"]
     branch: ["master"]
 
 dependencies:
···
   - name: build knot
     command: |
        go build -o knot.out ./cmd/knot
+
+  - name: build spindle
+    command: |
+       go build -o spindle.out ./cmd/spindle

.tangled/workflows/fmt.yml

···
 when:
-  - event: ["push"]
+  - event: ["push", "pull_request"]
     branch: ["master"]
 
 dependencies:

.tangled/workflows/test.yml

···
 when:
-  - event: ["push"]
-    branch: ["master", "test-ci"]
+  - event: ["push", "pull_request"]
+    branch: ["master"]
 
 dependencies:
   nixpkgs:

spindle/engine/envs_test.go

···
 			if got == nil {
 				got = EnvVars{}
 			}
-			assert.Equal(t, tt.want, got)
+			assert.ElementsMatch(t, tt.want, got)
 		})
 	}
 }