ci: Add dependabot.yml. Update lint.yml

Author: jpmckinney

.github/dependabot.yml

@@ -0,0 +1,6 @@
+version: 2
+updates:
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "daily"

.github/workflows/lint.yml

@@ -4,17 +4,16 @@ env:
   BASEDIR: https://raw.githubusercontent.com/open-contracting/standard-maintenance-scripts/main
 jobs:
   build:
+    if: github.event_name == 'push' || github.event.pull_request.head.repo.full_name != github.repository
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v2
-    - uses: actions/setup-python@v1
-      with:
-        python-version: 3.6
-    - uses: actions/cache@v1
-      with:
-        path: ~/.cache/pip
-        key: ${{ runner.os }}-pip-${{ hashFiles('.github/workflows/lint.yml') }}
-        restore-keys: |
-          ${{ runner.os }}-pip-
-    - run: curl -s -S --retry 3 $BASEDIR/tests/install.sh | bash -
-    - run: curl -s -S --retry 3 $BASEDIR/tests/script.sh | bash -
+      - uses: actions/checkout@v3
+      - uses: actions/setup-python@v4
+        with:
+          python-version: 3.8
+      - uses: actions/cache@v3
+        with:
+          path: ~/.cache/pip
+          key: ${{ runner.os }}-pip
+      - run: curl -s -S --retry 3 $BASEDIR/tests/install.sh | bash -
+      - run: curl -s -S --retry 3 $BASEDIR/tests/script.sh | bash -