COMPILER: Updates gcc version to 13.2

Updates all instances of GCC usage to 13.2 from older versions.

Change-Id: Ifc333a954093bc8af7a0ba338fed74b6ec106c4c
Signed-off-by: Matthew Dalzell <matthew.dalzell@arm.com>
diff --git a/build-docs.sh b/build-docs.sh
index bbf4580..ee84372 100755
--- a/build-docs.sh
+++ b/build-docs.sh
@@ -13,7 +13,7 @@
 
 set -ex
 
-export PATH=$PATH:$GCC_10_3_PATH
+export PATH=$PATH:$GCC_13_2_PATH
 
 mkdir -p ${WORKSPACE}/trusted-firmware-m/build/docs
 cd ${WORKSPACE}/trusted-firmware-m/build/docs