Fix workflows (#4948)

The problem was `CONAN_USERNAME` environment variable, which Conan 1.x uses as the default user in package references.

.github/actions/dependencies/action.yml

@@ -16,16 +16,25 @@ runs:
         conan export external/snappy snappy/1.1.10@
         conan export external/rocksdb rocksdb/6.29.5@
         conan export external/soci soci/4.0.3@
-    - name: try to authenticate to ripple Conan remote
-      id: remote
+    - name: add Ripple Conan remote
       shell: bash
       run: |
+        conan remote list
+        conan remote remove ripple || true
         # Do not quote the URL. An empty string will be accepted (with
         # a non-fatal warning), but a missing argument will not.
         conan remote add ripple ${{ env.CONAN_URL }} --insert 0
-        echo outcome=$(conan user --remote ripple ${{ env.CONAN_USERNAME }} \
-          --password ${{ env.CONAN_TOKEN }} >&2 && echo success || \
-          echo failure) | tee ${GITHUB_OUTPUT}
+    - name: try to authenticate to Ripple Conan remote
+      id: remote
+      shell: bash
+      run: |
+        # `conan user` implicitly uses the environment variables
+        # CONAN_LOGIN_USERNAME_<REMOTE> and CONAN_PASSWORD_<REMOTE>.
+        # https://docs.conan.io/1/reference/commands/misc/user.html#using-environment-variables
+        # https://docs.conan.io/1/reference/env_vars.html#conan-login-username-conan-login-username-remote-name
+        # https://docs.conan.io/1/reference/env_vars.html#conan-password-conan-password-remote-name
+        echo outcome=$(conan user --remote ripple --password >&2 \
+          && echo success || echo failure) | tee ${GITHUB_OUTPUT}
     - name: list missing binaries
       id: binaries
       shell: bash