ci: extract Leiningen installation into separate action

Author: kenranunderscore

.github/actions/install-leiningen/action.yml

@@ -0,0 +1,11 @@
+name: "install Leiningen"
+runs:
+  using: composite
+  steps:
+    - name: add pwd to PATH
+      shell: bash
+      run: echo "$(pwd)" >> "$GITHUB_PATH"
+    - name: install Leiningen
+      run: |
+        curl -LSs https://raw.githubusercontent.com/technomancy/leiningen/stable/bin/lein -o lein
+        chmod +x lein

.github/workflows/clojure.yml

@@ -6,12 +6,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v4
-    - name: add pwd to PATH
-      run: echo "$(pwd)" >> "$GITHUB_PATH"
-    - name: install Leiningen
-      run: |
-        curl -LSs https://raw.githubusercontent.com/technomancy/leiningen/stable/bin/lein -o lein
-        chmod +x lein
+    - uses: ./.github/actions/install-leiningen
     - name: install Clojure dependencies
       run: lein deps
     - name: run Clojure tests
@@ -22,12 +17,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v4
-    - name: add pwd to PATH
-      run: echo "$(pwd)" >> "$GITHUB_PATH"
-    - name: install Leiningen
-      run: |
-        curl -LSs https://raw.githubusercontent.com/technomancy/leiningen/stable/bin/lein -o lein
-        chmod +x lein
+    - uses: ./.github/actions/install-leiningen
     - run: lein codox
 
   notify-test-failures: