[Maintenance] Fix the case of `nearheap[data].asm`'s path

Previously broke the build on repository checkouts created by WSL git,
which enables per-directory case sensitivity for all directories within
the repo:

	https://devblogs.microsoft.com/commandline/per-directory-case-sensitivity-and-wsl/

Nice that this was the only path case issue in the entire repo!

th03_res_yume.asm

@@ -307,7 +307,7 @@ include libs/BorlandC/files[data].asm
 __heaplen	dw 0
 include libs/BorlandC/ioerror[data].asm
 include libs/BorlandC/stklen[data].asm
-include libs/borlandC/nearheap[data].asm
+include libs/BorlandC/nearheap[data].asm
 include libs/BorlandC/pathops[data].asm
 include libs/BorlandC/setvbuf[data].asm
 include libs/BorlandC/sysnerr[data].asm

th04_res_huma.asm

@@ -355,7 +355,7 @@ include libs/BorlandC/files[data].asm
 __heaplen	dw 0
 include libs/BorlandC/ioerror[data].asm
 include libs/BorlandC/stklen[data].asm
-include libs/borlandC/nearheap[data].asm
+include libs/BorlandC/nearheap[data].asm
 include libs/BorlandC/pathops[data].asm
 include libs/BorlandC/setvbuf[data].asm
 include libs/BorlandC/sysnerr[data].asm

th05_res_kso.asm

@@ -442,7 +442,7 @@ include libs/BorlandC/files[data].asm
 __heaplen	dw 0
 include libs/BorlandC/ioerror[data].asm
 include libs/BorlandC/stklen[data].asm
-include libs/borlandC/nearheap[data].asm
+include libs/BorlandC/nearheap[data].asm
 include libs/BorlandC/pathops[data].asm
 include libs/BorlandC/setvbuf[data].asm
 include libs/BorlandC/sysnerr[data].asm