Bump rustls-webpki 0.103.11 to 0.103.12

Patches RUSTSEC-2026-0098 and RUSTSEC-2026-0099 (X.509 name
constraint handling) for the rustls 0.23.x dependency tree.

The 0.101.7 copy pulled via rocket 0.5.1 is not addressed by this
change; it is anchored by rustls 0.21.x and requires a rocket
update.

Refs:
- https://rustsec.org/advisories/RUSTSEC-2026-0098.html
- https://rustsec.org/advisories/RUSTSEC-2026-0099.html

Cargo.lock

@@ -4485,7 +4485,7 @@ dependencies = [
  "once_cell",
  "ring",
  "rustls-pki-types",
- "rustls-webpki 0.103.11",
+ "rustls-webpki 0.103.12",
  "subtle",
  "zeroize",
 ]
@@ -4533,9 +4533,9 @@ dependencies = [
 
 [[package]]
 name = "rustls-webpki"
-version = "0.103.11"
+version = "0.103.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "20a6af516fea4b20eccceaf166e8aa666ac996208e8a644ce3ef5aa783bc7cd4"
+checksum = "8279bb85272c9f10811ae6a6c547ff594d6a7f3c6c6b02ee9726d1d0dcfcdd06"
 dependencies = [
  "ring",
  "rustls-pki-types",