dsa: bump crypto-bigint to v0.7 final release (#1247)

Release PR: RustCrypto/crypto-bigint#1218

Author: tarcieri

Cargo.lock

@@ -18,7 +18,7 @@ rust-version = "1.85"
 [dependencies]
 der = { version = "0.8", features = ["alloc"] }
 digest = "0.11"
-crypto-bigint = { version = "0.7.0-rc.28", default-features = false, features = ["alloc", "zeroize"] }
+crypto-bigint = { version = "0.7", default-features = false, features = ["alloc", "zeroize"] }
 crypto-primes = { version = "0.7.0-pre.9", default-features = false }
 rfc6979 = { version = "0.5.0-rc.5" }
 sha2 = { version = "0.11.0-rc.5", default-features = false }