tidy-up: syntax and code nits

- cmp-pkg-config.sh: replace `-r -f` with `-rf` to match rest of repo.
- configure.ac: add double quotes for robustness (not a bug).
- curl-openssl.m4: merge nested `if`s.
- CurlTests.c: drop `!= 0`, also to sync with m4.
- CurlTests.c: replace `example.com` with `localhost` in
  `gethostbyname()` feature test code. (compile-only, not a bug)
- GHA/http3-linux: drop literal `true` from bool expression.
- lib650: drop redundant `&`.
- move variable/call to left-hand side of equality checks, where
  missing.
- perl: detach `<`/`>` from filename in `open()`, where missing.
- schannel: apply two nit fixes lost in rebase.
- scripts/verify-release: drop redundant double quotes.
- scripts/verify-release: exit with error code on error.
- synctime: replace magic numbers with `sizeof()`.
- telnet: add missing parentheses to macro value.
- tests/Makefile.am: use single quotes.
- tool_operate: drop redundant `break` after `return` in VMS code.
- unit2413: drop unused NULL pointer + free call.
- unit2413: fix duplicate test case name.
- urlapi: drop redundant parentheses.
- urlapi: drop `CURL_UNCONST()` that became redundant.

Closes #22186

lib/urlapi.c

@@ -584,7 +584,7 @@ UNITTEST int ipv4_normalize(struct dynbuf *host)
       return HOST_NAME;
     curlx_dyn_reset(host);
     result = curlx_dyn_addf(host, "%u.%u.%u.%u",
-                            (parts[0]),
+                            parts[0],
                             ((parts[1] >> 16) & 0xff),
                             ((parts[1] >> 8) & 0xff),
                             (parts[1] & 0xff));
@@ -594,8 +594,8 @@ UNITTEST int ipv4_normalize(struct dynbuf *host)
       return HOST_NAME;
     curlx_dyn_reset(host);
     result = curlx_dyn_addf(host, "%u.%u.%u.%u",
-                            (parts[0]),
-                            (parts[1]),
+                            parts[0],
+                            parts[1],
                             ((parts[2] >> 8) & 0xff),
                             (parts[2] & 0xff));
     break;
@@ -605,10 +605,10 @@ UNITTEST int ipv4_normalize(struct dynbuf *host)
       return HOST_NAME;
     curlx_dyn_reset(host);
     result = curlx_dyn_addf(host, "%u.%u.%u.%u",
-                            (parts[0]),
-                            (parts[1]),
-                            (parts[2]),
-                            (parts[3]));
+                            parts[0],
+                            parts[1],
+                            parts[2],
+                            parts[3]);
     break;
   }
   if(result)
@@ -1961,7 +1961,7 @@ static CURLUcode url_sethost(CURLU *u, struct dynbuf *encp,
       bad = TRUE;
     curlx_free(decoded);
   }
-  else if(hostname_check(u, (char *)CURL_UNCONST(newp), n))
+  else if(hostname_check(u, newp, n))
     bad = TRUE;
   if(bad) {
     curlx_dyn_free(encp);