CI: set elements and bitcoind versions in one place.

We have them spread everywhere: unify them, and make setup.sh use install-bitcoind.sh

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

.github/workflows/ci.yaml

@@ -211,8 +211,6 @@ jobs:
     runs-on: ubuntu-22.04
     timeout-minutes: 120
     env:
-      BITCOIN_VERSION: "27.1"
-      ELEMENTS_VERSION: 23.2.1
       RUST_PROFILE: release  # Has to match the one in the compile step
       PYTEST_OPTS: --timeout=1200 --force-flaky
     needs:
@@ -319,8 +317,6 @@ jobs:
     runs-on: ubuntu-22.04
     timeout-minutes: 120
     env:
-      BITCOIN_VERSION: "27.1"
-      ELEMENTS_VERSION: 23.2.1
       RUST_PROFILE: release  # Has to match the one in the compile step
       CFG: compile-gcc
       PYTEST_OPTS: --test-group-random-seed=42 --timeout=1800 --force-flaky
@@ -389,8 +385,6 @@ jobs:
     runs-on: ubuntu-22.04
     timeout-minutes: 120
     env:
-      BITCOIN_VERSION: "27.1"
-      ELEMENTS_VERSION: 23.2.1
       RUST_PROFILE: release
       SLOW_MACHINE: 1
       TEST_DEBUG: 1