gci: Only install one of elementsd or bitcoind

We were accidentally testing against `bitcoind` rather than
`elementsd` which meant we believed everything was find, when in
reality some tests broke. By only installing the required daemon we
ensure that such a mixup causes a CI failure.

.github/scripts/install-bitcoind.sh

@@ -8,12 +8,21 @@ FILENAME="${DIRNAME}-x86_64-linux-gnu.tar.gz"
 EFILENAME="${EDIRNAME}-x86_64-linux-gnu.tar.gz"
 
 cd /tmp/
-wget "https://bitcoincore.org/bin/bitcoin-core-${BITCOIN_VERSION}/${FILENAME}"
-wget "https://github.com/ElementsProject/elements/releases/download/elements-${ELEMENTS_VERSION}/${EFILENAME}"
-tar -xf "${FILENAME}"
-tar -xf "${EFILENAME}"
-sudo mv "${DIRNAME}"/bin/* "/usr/local/bin"
-sudo mv "${EDIRNAME}"/bin/* "/usr/local/bin"
 
+# Since we inadvertently broke `elementsd` support in the past we only
+# want to download and enable the daemon that is actually going to be
+# used when running in CI. Otherwise we could end up accidentally
+# testing against `bitcoind` but still believe that we ran against
+# `elementsd`.
+if [ "$TEST_NETWORK" = "liquid-regtest" ]; then
+    wget "https://github.com/ElementsProject/elements/releases/download/elements-${ELEMENTS_VERSION}/${EFILENAME}"
+    tar -xf "${EFILENAME}"
+    sudo mv "${EDIRNAME}"/bin/* "/usr/local/bin"
+    rm -rf "${EFILENAME}" "${EDIRNAME}"
+else
+    wget "https://bitcoincore.org/bin/bitcoin-core-${BITCOIN_VERSION}/${FILENAME}"
+    tar -xf "${FILENAME}"
+    sudo mv "${DIRNAME}"/bin/* "/usr/local/bin"
+    rm -rf "${FILENAME}" "${DIRNAME}"
+fi
 
-rm -rf "${FILENAME}" "${EFILENAME}" "${DIRNAME}" "${EDIRNAME}"

.github/workflows/ci.yaml

@@ -275,6 +275,8 @@ jobs:
           poetry install
 
       - name: Install bitcoind
+        env:
+          TEST_NETWORK: ${{ matrix.TEST_NETWORK }}
         run: .github/scripts/install-bitcoind.sh
 
       - name: Download build