[CI] FreeBSD build (#17293)

Build FreeBSD on Github Actions

.ci/build-freebsd.sh

@@ -3,6 +3,7 @@
 # Pull all the submodules except llvm, opencv, libpng, sdl and curl
 # Note: Tried to use git submodule status, but it takes over 20 seconds
 # shellcheck disable=SC2046
+git config --global --add safe.directory .
 git submodule -q update --init --depth 1 $(awk '/path/ && !/llvm/ && !/opencv/ && !/libpng/ && !/libsdl-org/ && !/curl/ { print $3 }' .gitmodules)
 
 CONFIGURE_ARGS="

.ci/export-azure-vars.sh

@@ -1,13 +0,0 @@
-#!/bin/sh -e
-
-# Export variables for later stages of the Azure pipeline
-# Values done in this manner will appear as environment variables
-# in later stages.
-
-# From pure-sh-bible
-# Setting 'IFS' tells 'read' where to split the string.
-while IFS='=' read -r key val; do
-    # Skip over lines containing comments.
-    [ "${key##\#*}" ] || continue
-    echo "##vso[task.setvariable variable=$key]$val"
-done < ".ci/ci-vars.env"

.ci/export-cirrus-vars.sh

@@ -1,13 +0,0 @@
-#!/bin/sh -e
-
-# Export variables for later stages of the Cirrus pipeline
-# Values done in this manner will appear as environment variables
-# in later stages.
-
-# From pure-sh-bible
-# Setting 'IFS' tells 'read' where to split the string.
-while IFS='=' read -r key val; do
-    # Skip over lines containing comments.
-    [ "${key##\#*}" ] || continue
-    export "$key"="$val"
-done < ".ci/ci-vars.env"