[PATCH 2/8] autoregen.py: fix a pyright `reportConstantRedefinition` warning

[Simon Marchi <simon.marchi@efficios.com>]

Not a big deal, and this is certainly opinionated, but pyright tells me:

    /home/smarchi/src/builder/builder/containers/autoregen.py
      /home/smarchi/src/builder/builder/containers/autoregen.py:24:1 - error: "ENV" is constant (because it is uppercase) and cannot be redefined (reportConstantRedefinition)

Switch to a syntax that avoids redefinition of the variable.
---
 builder/containers/autoregen.py | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/builder/containers/autoregen.py b/builder/containers/autoregen.py
index 861a2ce79ef5..feee5878cac7 100755
--- a/builder/containers/autoregen.py
+++ b/builder/containers/autoregen.py
@@ -21,12 +21,15 @@ AUTOHEADER_BIN = next(name for name in autoheader_names if shutil.which(name))
 
 # autoconf-wrapper and automake-wrapper from Gentoo look at this environment variable.
 # It's harmless to set it on other systems though.
-ENV = f'WANT_AUTOCONF={AUTOCONF_BIN.split("-", 1)[1]} '
-ENV += f'WANT_AUTOMAKE={AUTOMAKE_BIN.split("-", 1)[1]} '
-
-ENV += f" AUTOCONF={AUTOCONF_BIN} "
-ENV += f" ACLOCAL={ACLOCAL_BIN} "
-ENV += f" AUTOMAKE={AUTOMAKE_BIN}"
+ENV = " ".join(
+    (
+        f'WANT_AUTOCONF={AUTOCONF_BIN.split("-", 1)[1]}',
+        f'WANT_AUTOMAKE={AUTOMAKE_BIN.split("-", 1)[1]}',
+        f"AUTOCONF={AUTOCONF_BIN}",
+        f"ACLOCAL={ACLOCAL_BIN}",
+        f"AUTOMAKE={AUTOMAKE_BIN}",
+    )
+)
 
 
 # Directories we should skip entirely because they're vendored or have different
-- 
2.44.0