ci: fix build-test job with --no-default-features, add miniscript/no-std

Until rust-miniscript removes the no-std feature we need to enable it
when --no-default-features is used to build bdk_wallet or the
whole workspace. See also the check-no-std job which does the same plus
enables the bdk_chain/hashbrown feature which is also needed to build
bdk_wallet with --no-default-features but is already enabled when
building the whole workspace.

.github/workflows/cont_integration.yml

@@ -25,7 +25,7 @@ jobs:
             clippy: true
           - version: 1.63.0 # MSRV
         features:
-          - --no-default-features
+          - --no-default-features --features miniscript/no-std
           - --all-features
     steps:
       - name: checkout