Cardano Updates

#2501 placed the shared patch at `builder/cabal-install-patches/`
and referenced it from `nix-tools/cabal-install-patches.nix` as
`../builder/cabal-install-patches/...`.  That breaks the static
nix-tools build (e.g. job
`aarch64-darwin.nix-tools.static.zipped.nix-tools-static-no-ifd`,
build 1046198 on ci.zw3rk.com) with

  error: access to absolute path '/nix/store/builder' is forbidden
         in pure evaluation mode (use '--impure' to override)

`cabalProject'` copies `src = ./.` (the nix-tools dir) to the
nix store and re-evaluates module paths from there.  A path that
escapes the source tree resolves to `/nix/store/<...>/../builder`
→ `/nix/store/builder`, which doesn't exist and is rejected
under pure-eval.

Move the patch into `nix-tools/cabal-install-patches/` so the
relative path (`./cabal-install-patches/...`) stays inside the
copied source tree.  Both the regular and static nix-tools
builds still import the same shared module, so they continue to
patch cabal-install identically.

Signed-off-by: Jenita <[email protected]>

Signed-off-by: Jenita <[email protected]>

* Bump blst with correct lastModified and narHash.
* Set libblst with matched flake input `0.3.15` explicit version string.
* Add GHA validate flake lock ci for both push and PR to catch 3rd party
contributions and pushes to master.
* Added an update to the changelog.md