Make meta directory root available and configurable via env var

Change-Id: I3c64dab14705d5e79012fbfede452df61c455d59

.ci/Jenkinsfile

@@ -36,6 +36,7 @@ pipeline {
 			environment {
 				DOCKER_BASE_IMAGE = "debian:bullseye"
 				DEPENDENCY_PYTHON = "python@3.8.2"
+				YASHCHIKI_META_DIR = "${WORKSPACE}/meta"
 				YASHCHIKI_RECIPE_PATH = "${WORKSPACE}/visionary_recipe.def"
 				YASHCHIKI_CACHES_ROOT = "${HOME}"
 				YASHCHIKI_SPACK_PATH = "${env.WORKSPACE}/spack"

.ci/Jenkinsfile_asic

@@ -38,6 +38,7 @@ pipeline {
 				DOCKER_BASE_IMAGE = "centos:7"
 				// versions from system packages
 				DEPENDENCY_PYTHON = "python@3.8.3"
+				YASHCHIKI_META_DIR = "${WORKSPACE}/meta"
 				YASHCHIKI_RECIPE_PATH = "${WORKSPACE}/asic_recipe.def"
 				YASHCHIKI_CACHES_ROOT = "${HOME}"
 				YASHCHIKI_SPACK_PATH = "${env.WORKSPACE}/spack"

.ci/commons.sh

@@ -121,7 +121,7 @@ export PRESERVED_PACKAGES_INSIDE
 export PRESERVED_PACKAGES_OUTSIDE
 
 META_DIR_INSIDE="/opt/meta"
-META_DIR_OUTSIDE="$(get_host_env WORKSPACE)${META_DIR_INSIDE}"
+META_DIR_OUTSIDE="$(get_host_env YASHCHIKI_META_DIR)${META_DIR_INSIDE}"
 export META_DIR_INSIDE
 export META_DIR_OUTSIDE