fix: cite the mariani tree for its symbol tables

Debugger_Symbols.cpp:46-53, 774-806 and 814-817 read the same in sh95014/AppleWin at 51893ca, the tree Mariani builds.

emulators/mariani.yml

@@ -447,7 +447,7 @@ files:
     size: 13444
     md5: 034527d42a96d0f39977cb85c6a8f2d8
     sha1: fcfbbb25e06f58d13e762b02bfd468c834d98fc8
-    source_ref: "upstream source/Debugger/Debugger_Symbols.cpp:46, 774, 814-817, source source/Debugger/Debug.cpp:9495-9496"
+    source_ref: "source source/Debugger/Debugger_Symbols.cpp:46, 774, 814-817, source source/Debugger/Debug.cpp:9495-9496"
     note: >
       Preloaded into the Main table when the emulator starts. Read from the
       support directory first, then from the bundle. Parsed as lines of address
@@ -460,7 +460,7 @@ files:
     size: 15378
     md5: 7253a9ba7d7ca807016f5adc0207dd7b
     sha1: 496a0bd1af463fce81b362da9e4757a993e355d5
-    source_ref: "upstream source/Debugger/Debugger_Symbols.cpp:47, 774, 814-817, source source/Debugger/Debug.cpp:9498-9499"
+    source_ref: "source source/Debugger/Debugger_Symbols.cpp:47, 774, 814-817, source source/Debugger/Debug.cpp:9498-9499"
     note: "Preloaded into the Basic table when the emulator starts."
 
   - name: A2_DOS33.SYM2
@@ -469,7 +469,7 @@ files:
     size: 2380
     md5: 88bd69906b4b3109b3f31472fb4b47f4
     sha1: 51cc84e2cbd9bd61d50a0931cdae0a2ef0a57d6c
-    source_ref: "upstream source/Debugger/Debugger_Symbols.cpp:53, 774-806, source source/Debugger/Debug.cpp:9502-9503"
+    source_ref: "source source/Debugger/Debugger_Symbols.cpp:53, 774-806, source source/Debugger/Debug.cpp:9502-9503"
     note: >
       Preloaded into the DOS33 table when the emulator starts. The .SYM2
       extension routes it through the debugger script reader instead of the