ci: only install postgres 17 since that's what's used for testing

Signed-off-by: Richard Zak <richard.j.zak@gmail.com>

Author: rjzak

.github/workflows/test.yml

@@ -33,7 +33,7 @@ jobs:
           sudo apt-get update
           sudo apt-get install -y bison build-essential clang flex libreadline-dev libxml2-dev libxslt-dev libssl-dev pkg-config xsltproc zlib1g-dev
           cargo install cargo-pgrx --version 0.19.1 --locked
-          cargo pgrx init
+          cargo pgrx init --pg17=download
 
       - name: Test
         run: cargo pgrx test