docs(formal): remove dead change_history_table import

The change_history_table rendering is handled exclusively by core.typ's
auto-appended Appendices section. This import was never called from these
consumer files.

Also regenerates the PDFs after the upstream core.typ update (adds
extra_appendix_body parameter; no observable change for this project).

Author: abitofhelp

docs/formal/software_design_specification.pdf

@@ -17,7 +17,7 @@
 // SPDX-License-Identifier: BSD-3-Clause
 // ============================================================================
 
-#import "core.typ": formal_doc, change_history_table
+#import "core.typ": formal_doc
 
 #let doc = (
   authors: ("Michael Gardner",),

docs/formal/software_design_specification.typ

@@ -17,7 +17,7 @@
 // SPDX-License-Identifier: BSD-3-Clause
 // ============================================================================
 
-#import "core.typ": change_history_table, formal_doc
+#import "core.typ": formal_doc
 
 #let doc = (
   authors: ("Michael Gardner",),

docs/formal/software_requirements_specification.pdf

@@ -17,7 +17,7 @@
 // SPDX-License-Identifier: BSD-3-Clause
 // ============================================================================
 
-#import "core.typ": formal_doc, change_history_table
+#import "core.typ": formal_doc
 
 #let doc = (
   title: "Software Test Guide",