ci: fix Windows OS CI due to path length (#500)

Summary:
[sl] ci: fix Windows OS CI due to path length

Currently our OSS CI on Windows is failing due to some paths being too long (e.g., `C:/Users/runneradmin/.cargo/git/checkouts/fbthrift-abf000ee5c7fcc50/c757ec4/thrift/website/src/json/ref/cpp/f/struct/special/structapache_1_1thrift_1_1op_1_1detail_1_1AnyOp_3_01type_1_1cpp__type_3_01T_00_01type_1_1map_3_01KTag_00_01VTag_01_4_01_4_01_4/assign.json`)

Since the length of that path is just above the Windows max length (263 vs. 260). This diff tries to alleviate that by setting the `core.longpaths` option for the git system config.

Pull Request resolved: #500

Test Plan:
Ran GitHub actions on a personal fork of the repo.

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Stack created with [Sapling](https://sapling-scm.com). Best reviewed with [ReviewStack](https://reviewstack.dev/facebook/sapling/pull/500).
* __->__ #500

Reviewed By: bolinfest

Differential Revision: D42727420

Pulled By: sggutier

fbshipit-source-id: 3cf908f8e9537f20d796dcaa97292512f1172919

.github/workflows/sapling-cli-windows-amd64-release.yml

@@ -15,6 +15,8 @@ jobs:
       run: git config --global --add safe.directory "$PWD"
     - name: rustup
       run: rustup default stable
+    - name: Support longpaths
+      run: git config --system core.longpaths true
     - name: openssl
       run: vcpkg install openssl:x64-windows-static-md
     - name: integrate vcpkg

ci/gen_workflows.py

@@ -297,6 +297,10 @@ def gen_windows_release(self) -> str:
                 {"name": "Checkout Code", "uses": "actions/checkout@v3"},
                 grant_repo_access(),
                 {"name": "rustup", "run": "rustup default stable"},
+                {
+                    "name": "Support longpaths",
+                    "run": "git config --system core.longpaths true",
+                },
                 # The "x64-windows-static-md" triple is what the Rust openssl
                 # crate expects on Windows when it goes looking for the vcpkg
                 # install.