Removed ca from credential signatures.

[Randy808]

If consensus is reached on this change, it should be merged after #454

[nepet]

Looks good to me, only some minor complaints from the formatter on credentials.rs.

Diff in /home/runner/work/greenlight/greenlight/libs/gl-client-py/src/credentials.rs at line 182:
                 let d = creds.clone().with_ca(ca);
                 let inner = UnifiedCredentials::Device(d);
                 Self { inner }
-            },
+            }
         }
     }
 }
Diff in /home/runner/work/greenlight/greenlight/libs/gl-client/src/credentials.rs at line 193:
             cert: cert.into(),
             key: key.into(),
             rune: rune.into(),
-            ca
+            ca,
         }
     }
 
Diff in /home/runner/work/greenlight/greenlight/libs/gl-client/src/credentials.rs at line 200:
-    pub fn with_ca<V>(self, ca: V) -> Self 
+    pub fn with_ca<V>(self, ca: V) -> Self
     where
         V: Into<Vec<u[8](https://github.com/Blockstream/greenlight/actions/runs/9320196028/job/25656453262?pr=456#step:4:9)>>,
     {
Diff in /home/runner/work/greenlight/greenlight/libs/gl-client/src/credentials.rs at line 248:
     fn tls_config(&self) -> TlsConfig {
         tls::TlsConfig::with(&self.cert, &self.key, &self.ca)
     }
-
 }

[nepet]

Oh and this conflicts with the backend tests: the fixtures there need to be fixed after we merged this

[cdecker]

Rebasing, merging, and then fixing up the backend to match this, once we have #408 merged as well (since that's the version the backend is working against atm).