chore: drop * wildcard from CODEOWNERS to stop Dependabot review pings (#58)

The catch-all `* @hyperpolymath` line in CODEOWNERS causes GitHub to
auto-request review on every Dependabot PR (since every PR touches at
least one owned path under `*`). With the sole maintainer being the same
user, those review requests are pure notification noise.

This drops the wildcard line while preserving any path-specific
ownership and SPDX/license headers. Path-specific lines are intentional
and stay.

Human PRs from collaborators still trigger path-owner review where
applicable; Dependabot PRs typically only touch root manifest files
which are no longer matched.

Author: hyperpolymath

.github/CODEOWNERS

@@ -2,9 +2,8 @@
 # CODEOWNERS - Code ownership for ECHIDNA
 # See https://docs.github.com/en/repositories/managing-your-repositorys-settings-and-features/customizing-your-repository/about-code-owners
 
-# Default owner for all files
-* @hyperpolymath
-
+# Default owner for all files
+
 # Core prover backends
 /src/rust/provers/ @hyperpolymath
 /src/rust/core.rs @hyperpolymath
@@ -22,4 +21,4 @@
 /Containerfile @hyperpolymath
 
 # SCM and machine-readable metadata
-/.machine_readable/ @hyperpolymath
+/.machine_readable/ @hyperpolymath