fix(ci): use pkgconf (not pkgconfig) for Alpine musl targets

Alpine Linux requires 'pkgconf' package name, not 'pkgconfig'.
This fixes OpenSSL header detection errors in cross containers.

Author: pRizz

Cross.toml

@@ -3,14 +3,14 @@
 
 [target.x86_64-unknown-linux-musl]
 pre-build = [
-  # Alpine-based musl images use apk
-  "apk add --no-cache openssl-dev pkgconfig || (apt-get update && apt-get install -y libssl-dev pkg-config)"
+  # Alpine-based musl images use apk; pkgconf is required (not pkgconfig)
+  "apk add --no-cache pkgconf openssl-dev || (apt-get update && apt-get install -y pkg-config libssl-dev)"
 ]
 
 [target.aarch64-unknown-linux-musl]
 pre-build = [
-  # Alpine-based musl images use apk
-  "apk add --no-cache openssl-dev pkgconfig || (apt-get update && apt-get install -y libssl-dev pkg-config)"
+  # Alpine-based musl images use apk; pkgconf is required (not pkgconfig)
+  "apk add --no-cache pkgconf openssl-dev || (apt-get update && apt-get install -y pkg-config libssl-dev)"
 ]
 
 [target.aarch64-unknown-linux-gnu]