export GIT_COMMIT=$(cat src/runtime/version) in Makefile (AppImage#104)

Closes AppImage#103

Author: probonopd

src/runtime/Makefile

@@ -1,5 +1,6 @@
+GIT_COMMIT := $(shell cat version)
 CC            = gcc
-CFLAGS        = -std=gnu99 -Os -D_FILE_OFFSET_BITS=64 -DGIT_COMMIT=\"${GIT_COMMIT}\" -T data_sections.ld -ffunction-sections -fdata-sections -Wl,--gc-sections -static -Wall -Werror
+CFLAGS        = -std=gnu99 -Os -D_FILE_OFFSET_BITS=64 -DGIT_COMMIT=\"$(GIT_COMMIT)\" -T data_sections.ld -ffunction-sections -fdata-sections -Wl,--gc-sections -static -Wall -Werror
 LIBS          = -lsquashfuse -lsquashfuse_ll -lzstd -lz -lfuse3
 
 all: runtime