Tidy up some logs that have a prefix. (#4443)

We haven't needed these for ages, Rust adds them to the log lines.

ElementX/Sources/Other/Pills/MessageText.swift

@@ -63,7 +63,7 @@ struct MessageText: UIViewRepresentable {
             do {
                 attributedString = try AttributedString(textView.attributedText, including: \.elementX)
             } catch {
-                MXLog.error("[MessageText] Failed to update attributedString: \(error)]")
+                MXLog.error("Failed to update attributedString: \(error)]")
                 return
             }
         }

ElementX/Sources/Other/Pills/PillAttachmentViewProvider.swift

@@ -37,7 +37,7 @@ final class PillAttachmentViewProvider: NSTextAttachmentViewProvider, NSSecureCo
 
         guard let textAttachment = textAttachment as? PillTextAttachment,
               let pillData = textAttachment.pillData else {
-            MXLog.failure("[PillAttachmentViewProvider]: attachment is missing data or not of expected class")
+            MXLog.failure("Attachment is missing data or not of expected class")
             return
         }
         
@@ -51,7 +51,7 @@ final class PillAttachmentViewProvider: NSTextAttachmentViewProvider, NSSecureCo
             context = PillContext(timelineContext: timelineContext, data: pillData)
             mediaProvider = timelineContext.mediaProvider
         } else {
-            MXLog.failure("[PillAttachmentViewProvider]: missing room context")
+            MXLog.failure("Missing room context")
             return
         }