Remove patch to use absl::optional in third_party/shell-encryption

std::optional is just fine and preferred now.

Bug: 40242125
Change-Id: I57f7e0207b75a60124964c3acc20b971c08c14f5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5698386
Commit-Queue: Amr Aboelkher <amraboelkher@chromium.org>
Reviewed-by: Amr Aboelkher <amraboelkher@chromium.org>
Auto-Submit: David Benjamin <davidben@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1326712}
NOKEYCHECK=True
GitOrigin-RevId: 24ebcea5cee012b29124a4a4c3c8cd3c4c8e462c

patches/0002-Use-absl-instead-of-std-optional.patch

diff --git a/patches/0002-Use-absl-instead-of-std-optional.patch b/patches/0002-Use-absl-instead-of-std-optional.patch
deleted file mode 100644
index 7e6457d..0000000
--- a/patches/0002-Use-absl-instead-of-std-optional.patch
+++ /dev/null
@@ -1,13 +0,0 @@
-diff --git a/ntt_parameters.h b/ntt_parameters.h
-index c3da197..55671ec 100644
---- a/ntt_parameters.h
-+++ b/ntt_parameters.h
-@@ -168,7 +168,7 @@ struct NttParameters {
-   ~NttParameters() = default;
- 
-   int number_coeffs;
--  std::optional<ModularInt> n_inv_ptr;
-+  absl::optional<ModularInt> n_inv_ptr;
-   std::vector<ModularInt> psis_bitrev;
-   std::vector<ModularInt> psis_inv_bitrev;
-   std::vector<unsigned int> bitrevs;

src/ntt_parameters.h

diff --git a/src/ntt_parameters.h b/src/ntt_parameters.h
index dc56ab6..beceed2 100644
--- a/src/ntt_parameters.h
+++ b/src/ntt_parameters.h
@@ -169,7 +169,7 @@
   ~NttParameters() = default;
 
   int number_coeffs;
-  absl::optional<ModularInt> n_inv_ptr;
+  std::optional<ModularInt> n_inv_ptr;
   std::vector<ModularInt> psis_bitrev;
   std::vector<ModularInt> psis_inv_bitrev;
   std::vector<unsigned int> bitrevs;