Switch to Java 17 in the CI

Author: hamzaremmal

Diff for: .github/workflows/ci.yaml

@@ -65,8 +65,8 @@ jobs:
            && github.repository == 'lampepfl/dotty'
          )"
     steps:
-      - name: Set JDK 16 as default
-        run: echo "/usr/lib/jvm/java-16-openjdk-amd64/bin" >> $GITHUB_PATH
+      - name: Set JDK 17 as default
+        run: echo "/usr/lib/jvm/java-17-openjdk-amd64/bin" >> $GITHUB_PATH
 
       - name: Reset existing repo
         run: git -c "http.https://github.com/.extraheader=" fetch --recurse-submodules=no "https://github.com/lampepfl/dotty" && git reset --hard FETCH_HEAD || true
@@ -116,8 +116,8 @@ jobs:
          )"
 
     steps:
-      - name: Set JDK 16 as default
-        run: echo "/usr/lib/jvm/java-16-openjdk-amd64/bin" >> $GITHUB_PATH
+      - name: Set JDK 17 as default
+        run: echo "/usr/lib/jvm/java-17-openjdk-amd64/bin" >> $GITHUB_PATH
 
       - name: Reset existing repo
         run: git -c "http.https://github.com/.extraheader=" fetch --recurse-submodules=no "https://github.com/lampepfl/dotty" && git reset --hard FETCH_HEAD || true
@@ -170,8 +170,8 @@ jobs:
          )"
 
     steps:
-      - name: Set JDK 16 as default
-        run: echo "/usr/lib/jvm/java-16-openjdk-amd64/bin" >> $GITHUB_PATH
+      - name: Set JDK 17 as default
+        run: echo "/usr/lib/jvm/java-17-openjdk-amd64/bin" >> $GITHUB_PATH
 
       - name: Reset existing repo
         run: git -c "http.https://github.com/.extraheader=" fetch --recurse-submodules=no "https://github.com/lampepfl/dotty" && git reset --hard FETCH_HEAD || true