GitHub workflow update (test multiple Bitcoin Core versions)

* Add support for testing against multiple Bitcoin Core versions, add
  0.18.0 (oldest officially support for test suite) and 24.0.1 (latest
  stable release). Previously we tested against hardcoded 0.19.1. IMO
  testing against oldest supported and latest makes sense, if tests pass
  on both, they should pass on releases inbetween too, unless there is
  some behaviour affecting us changed twice.
* Update actions/cache from v2 to v3.

Also changed Core downloads from bitcoin.org to bitcoincore.org.

.github/workflows/unittests.yml

@@ -10,6 +10,7 @@ jobs:
       matrix:
         os: [macos-latest, ubuntu-latest]
         python-version: ["3.7", "3.8", "3.9", "3.10"]
+        bitcoind-version: ["0.18.0", "24.0.1"]
 
     steps:
       - uses: actions/checkout@v2
@@ -19,7 +20,7 @@ jobs:
           python-version: ${{ matrix.python-version }}
       - name: Cache venv
         id: cache-venv
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         env:
           cache-name: venv
         with:
@@ -35,16 +36,19 @@ jobs:
       - name: Lint with flake8
         run: ./jmvenv/bin/flake8 -v jmclient jmbase jmbitcoin jmdaemon scripts
       - name: Cache bitcoind
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         env:
           cache-name: bitcoind
+          BITCOIND_VERSION: ${{ matrix.bitcoind-version }}
         with:
           path: ~/bitcoin/*/bin/bitcoin*
-          key: ${{ runner.os }}-${{ env.cache-name }}-${{ hashFiles('test/testrunner/install_bitcoind.sh') }}
+          key: ${{ runner.os }}-${{ env.cache-name }}-${{ env.BITCOIND_VERSION }}-${{ hashFiles('test/testrunner/install_bitcoind.sh') }}
       - name: Install bitcoind
+        env:
+          BITCOIND_VERSION: ${{ matrix.bitcoind-version }}
         run: ./test/testrunner/install_bitcoind.sh
       - name: Cache miniircd
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         env:
           cache-name: miniircd
         with:

test/testrunner/install_bitcoind.sh

@@ -2,12 +2,19 @@
 
 set -ev
 
-export BITCOIND_VERSION=0.19.1
+if [[ -z "$BITCOIND_VERSION" ]]; then
+    echo "BITCOIND_VERSION must be set"
+    exit 1
+fi
 
 if [[ "$(uname)" == "Linux" ]]; then
     platform="x86_64-linux-gnu"
 elif [[ "$(uname)" == "Darwin" ]]; then
-    platform="osx64"
+    if [[ $BITCOIND_VERSION > 23.0 || $BITCOIND_VERSION == 23.0 ]]; then
+        platform="x86_64-apple-darwin"
+    else
+        platform="osx64"
+    fi
 else
     echo "Unsupported platform: $(uname)"
     exit 1