tidy-up: miscellaneous

- `N byte` -> `N-byte` or `N bytes`.
- INTERNALS.md: language tweaks.
- schannel: language tweak in comment/error message.
- socks_gssapi, socks_sspi: simplify composing an error message.
  (at a cost of 8 extra constant string bytes.)
- m4/curl-compilers.m4: fix typo in link (in comment).
- contrithanks.sh: fix indent, drop stray `;` terminator.
- lib, src, tests: drop/fix a bunch of badwords.
- fix typos in comments.
- fix indent, stray spaces.

Some of these spotted by GitHub Code Quality and Copilot

Closes #22009

lib/cf-https-connect.c

@@ -309,7 +309,7 @@ static enum alpnid cf_hc_get_httpsrr_alpn(struct Curl_cfilter *cf,
   if(Curl_httpsrr_applicable(data, rr) && !rr->no_def_alpn) {
     for(i = 0; i < CURL_ARRAYSIZE(rr->alpns); ++i) {
       enum alpnid alpn_rr = (enum alpnid)rr->alpns[i];
-      if(alpn_rr == not_this_one) /* don't want this one */
+      if(alpn_rr == not_this_one) /* do not want this one */
         continue;
       switch(alpn_rr) {
       case ALPN_h3: