fix(dependencies): change payjoin version specifier 1.0.0-rc.1 to =1.0.0-rc.1

Cargo's version resolution always updates to the latest patch version.
If that patch introduces breaking changes, it breaks your application.

This happened after Payjoin released version 1.0.0-rc.2. Because the
version specified for bdk-cli was 1.0.0-rc.1, a fresh install
automatically updated to the newer patch.

To resolve this without migrating to the latest Payjoin API, and to
prevent future breakages from subsequent 1.0.0-rc.x releases, this
commit pins the Payjoin version strictly to =1.0.0-rc.1.

Author: nymius

Cargo.toml

@@ -33,7 +33,7 @@ bdk_esplora = { version = "0.22.1", features = ["async-https", "tokio"], optiona
 bdk_kyoto = { version = "0.15.1", optional = true }
 bdk_redb = { version = "0.1.0", optional = true }
 shlex = {  version = "1.3.0", optional = true }
-payjoin = { version = "1.0.0-rc.1", features = ["v1", "v2", "io", "_test-utils"], optional = true}
+payjoin = { version = "=1.0.0-rc.1", features = ["v1", "v2", "io", "_test-utils"], optional = true}
 reqwest = { version = "0.12.23", default-features = false, optional = true }
 url = { version = "2.5.4", optional = true }