Update .envrc.

.envrc

@@ -1,10 +1,10 @@
-if command -v guix; then
+if has guix; then
   GUIX_PROFILE="${PWD}/.guix-root"
   rm -f "$GUIX_PROFILE"
   eval "$(guix time-machine -C channels-lock.scm -- shell -r "$GUIX_PROFILE" -D -f guix.scm -m manifest.scm --search-paths)"
 
   # Add development scripts to PATH
-  export PATH="$(pwd)/scripts:${PATH}"
+  PATH_add "$(pwd)/scripts"
 
   venv_dir=".venv"
 
@@ -21,14 +21,8 @@ if command -v guix; then
   clear
   git-cal --author="$(git config user.name)"
 
-  run-tests () {
-    run_pipeline_tests.sh
-  }
-  export_function run-tests
   cat << EOF
 
-run-tests       Runs pytest in the current directory
-
 The 'scripts' directory has been added to your PATH: you can now invoke scripts without typing the relative path.
 
 EOF