CI AJA: use release branch

Use rather branch release instead of main because in main things may
break sometimes.

Eg. currently (libajantv2 commit 9060cc4a), ntv2m31enums.h is not
installed but ntv2utils.h includes that.

Author: MartinPulec

.github/scripts/install-common-deps.sh

@@ -36,7 +36,8 @@ cineform-0001-CMakeList.txt-remove-output-lib-name-force-UNIX.patch
 )}
 
 download_build_aja() {
-        git clone --depth 1 https://github.com/aja-video/libajantv2.git
+        aja_url=https://github.com/aja-video/libajantv2.git
+        git clone -b release --depth 1 $aja_url
         # TODO TOREMOVE this workarounds when not needed
         tr -d '\n' < libajantv2/VERSION.txt > ver-fix-no-NL$$.txt &&
                 mv ver-fix-no-NL$$.txt libajantv2/VERSION.txt