[ci] switch CI runner from Ubuntu 20.04 to 22.04

Signed-off-by: Gary Guo <gary.guo@lowrisc.org>

.github/workflows/ci.yml

@@ -25,7 +25,7 @@ on:
 jobs:
   lint_dv:
     name: Run quality checks (Lint and DV)
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     steps:
       - uses: actions/checkout@v4
         with:

ci/install-build-deps.sh

@@ -26,7 +26,7 @@ if [ -z "$GITHUB_ACTIONS" ]; then
 fi
 
 case "$ID-$VERSION_ID" in
-  ubuntu-16.04|ubuntu-18.04|ubuntu-20.04)
+  ubuntu-20.04|ubuntu-22.04)
     # Curl must be available to get the repo key below.
     $SUDO_CMD apt-get update
     $SUDO_CMD apt-get install -y curl