build: run codespell on almost all files

Ignore only third-party/vendored files (such as license files and files
in m4/).

And ignore more words to fix the following errors:

    $ make codespell
    Running codespell...
    ./README:484: als ==> also
    ./README:646: Shotcut ==> Shortcut
    ./RELNOTES:516: als ==> also
    ./etc/inc/disable-common.inc:506: chage ==> change, charge
    ./etc/apparmor/firejail-default:35: readby ==> read, read by
    ./etc/apparmor/firejail-default:36: readby ==> read, read by
    ./etc/profile-a-l/als.profile:1: als ==> also
    ./etc/profile-a-l/als.profile:5: als ==> also
    make: *** [Makefile:374: codespell] Error 65
    $ codespell --version
    2.2.5

1 files changed, 6 insertions, 2 deletions

diff --git a/Makefile b/Makefile
index 7bbdcbfd3..c04d721cf 100644
--- a/Makefile
+++ b/Makefile
@@ -366,12 +366,16 @@ cppcheck: clean
 scan-build: clean
         scan-build $(MAKE)
 
+# TODO: Old codespell versions (such as v2.1.0 in CI) have issues with
+# contrib/syscalls.sh
 .PHONY: codespell
 codespell:
         @printf 'Running %s...\n' $@
-        @codespell --ignore-regex "UE|creat|doas|ether|isplay|shotcut" \
+        @codespell --ignore-regex 'UE|als|chage|creat|doas|ether|isplay|readby|[Ss]hotcut' \
           -S *.gz,*.o,*.so \
-          src test
+          -S COPYING,m4 \
+          -S ./contrib/syscalls.sh \
+          .
 
 .PHONY: print-env
 print-env: