build(deps): bump ecdsa_fun from `da6ffd2` to `9657d8c`

Bumps [ecdsa_fun](https://github.com/LLFourn/secp256kfun) from `da6ffd2` to `9657d8c`.
- [Release notes](https://github.com/LLFourn/secp256kfun/releases)
- [Commits](da6ffd2ef4...9657d8c12f)

---
updated-dependencies:
- dependency-name: ecdsa_fun
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Cargo.lock

@@ -1031,7 +1031,7 @@ checksum = "5caaa75cbd2b960ff1e5392d2cfb1f44717fffe12fc1f32b7b5d1267f99732a6"
 [[package]]
 name = "ecdsa_fun"
 version = "0.7.1"
-source = "git+https://github.com/LLFourn/secp256kfun#da6ffd2ef4d58c84d508428356c92d92d5f11ac4"
+source = "git+https://github.com/LLFourn/secp256kfun#9657d8c12fd26df5e57254a0063eaf41082a38ca"
 dependencies = [
  "bincode",
  "rand_chacha 0.3.1",
@@ -3439,7 +3439,7 @@ dependencies = [
 [[package]]
 name = "secp256kfun"
 version = "0.7.1"
-source = "git+https://github.com/LLFourn/secp256kfun#da6ffd2ef4d58c84d508428356c92d92d5f11ac4"
+source = "git+https://github.com/LLFourn/secp256kfun#9657d8c12fd26df5e57254a0063eaf41082a38ca"
 dependencies = [
  "digest 0.10.5",
  "rand_core 0.6.2",
@@ -3661,7 +3661,7 @@ dependencies = [
 [[package]]
 name = "sigma_fun"
 version = "0.4.1"
-source = "git+https://github.com/LLFourn/secp256kfun#da6ffd2ef4d58c84d508428356c92d92d5f11ac4"
+source = "git+https://github.com/LLFourn/secp256kfun#9657d8c12fd26df5e57254a0063eaf41082a38ca"
 dependencies = [
  "curve25519-dalek-ng",
  "digest 0.10.5",