[Update]: improve workflows (#358)

* add `paths-ignore`
* add `concurrency`

Author: yutaro-sakamoto

.github/workflows/pull-request.yml

@@ -3,6 +3,16 @@ name: test on pull request
 on:
   pull_request:
     types: [opened, reopened, review_requested, synchronize]
+    paths-ignore:
+      - '*.md'
+      - 'ChangeLog'
+      - 'NEWS'
+      - 'README'
+      - 'COPYING'
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
 
 env:
   CLASSPATH: ":/usr/lib/opensourcecobol4j/libcobj.jar"

.github/workflows/push.yml

@@ -2,6 +2,16 @@ name: test on push
 
 on:
   push:
+    paths-ignore:
+      - '*.md'
+      - 'ChangeLog'
+      - 'NEWS'
+      - 'README'
+      - 'COPYING'
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
 
 env:
   CLASSPATH: ":/usr/lib/opensourcecobol4j/libcobj.jar"