fix(ci): exclude subxt crates from umbrella runtime-full to fix wasm32v1-none build

The pez-kitchensink-runtime wasm build was failing because pezkuwi-subxt-signer
(a client-side signing utility) was included in the umbrella's runtime-full
feature. This pulled in regex with workspace-inherited default features (std)
and thiserror v1 which doesn't support no-std, both causing compilation failures
on the wasm32v1-none target.

Changes:
- Exclude pezkuwi-subxt-{signer,core,macro,metadata} from runtime-full in the
  umbrella generator script (they are client-side crates, not runtime crates)
- Fix pezkuwi-subxt-signer's regex dependency to use explicit version with
  default-features=false (Cargo 2021 edition silently ignores default-features
  override with workspace=true when workspace has defaults enabled)
- Add regex/perf to signer's std feature for full performance when std is on

vendor/pezkuwi-subxt/signer/Cargo.toml

@@ -32,6 +32,7 @@ std = [
 	"pezsp-crypto-hashing/std",
 	"pezsp-keyring/std",
 	"regex/std",
+	"regex/perf",
 	"schnorrkel?/std",
 	"scrypt?/std",
 	"secp256k1?/std",
@@ -97,7 +98,7 @@ keccak-hash = { workspace = true, optional = true }
 pbkdf2 = { workspace = true }
 pezkuwi-subxt-core = { workspace = true, optional = true, default-features = false }
 pezsp-crypto-hashing = { workspace = true }
-regex = { workspace = true, features = ["unicode"] }
+regex = { version = "1.10.2", default-features = false, features = ["unicode"] }
 schnorrkel = { workspace = true, optional = true, features = ["getrandom"] }
 secp256k1 = { workspace = true, optional = true, features = [
 	"alloc",