[ceres] Add feature schur (#36792)

This small PR adds a default feature `schur` to control the
`SCHUR_SPECIALIZATIONS` option in Ceres. It remains on by default.

As described briefly in the
[documentation](http://ceres-solver.org/installation.html#options-controlling-ceres-configuration),
`SCHUR_SPECIALIZATIONS` enables some template specializations which
improve runtime performance of the `SPARSE_SCHUR` solver, but it
requires a large number of explicit instantiations and generates large
object files—large enough to require `/bigobj` in MSVC. This can cause
issues with some compilers particularly in constrained environments.

- [x] Changes comply with the [maintainer
guide](https://github.com/microsoft/vcpkg-docs/blob/main/vcpkg/contributing/maintainer-guide.md).
- [ ] ~~SHA512s are updated for each updated download.~~
- [ ] ~~The "supports" clause reflects platforms that may be fixed by
this new version.~~
- [ ] ~~Any fixed [CI
baseline](https://github.com/microsoft/vcpkg/blob/master/scripts/ci.baseline.txt)
entries are removed from that file.~~
- [ ] ~~Any patches that are no longer applied are deleted from the
port's directory.~~
- [x] The version database is fixed by rerunning `./vcpkg x-add-version
--all` and committing the result.
- [x] Only one version is added to each modified port's versions file.

ports/ceres/portfile.cmake

@@ -28,6 +28,7 @@ file(REMOVE "${SOURCE_PATH}/cmake/FindMETIS.cmake")
 
 vcpkg_check_features(OUT_FEATURE_OPTIONS FEATURE_OPTIONS
     FEATURES
+        "schur"             SCHUR_SPECIALIZATIONS
         "suitesparse"       SUITESPARSE
         "cxsparse"          CXSPARSE
         "lapack"            LAPACK

ports/ceres/vcpkg.json

@@ -1,7 +1,7 @@
 {
   "name": "ceres",
   "version": "2.1.0",
-  "port-version": 4,
+  "port-version": 5,
   "description": "non-linear optimization package",
   "homepage": "https://github.com/ceres-solver/ceres-solver",
   "license": "Apache-2.0",
@@ -48,6 +48,9 @@
         "lapack"
       ]
     },
+    "schur": {
+      "description": "Enable fixed-size Schur specializations in Ceres"
+    },
     "suitesparse": {
       "description": "SuiteSparse support for Ceres",
       "dependencies": [

versions/baseline.json

@@ -1526,7 +1526,7 @@
     },
     "ceres": {
       "baseline": "2.1.0",
-      "port-version": 4
+      "port-version": 5
     },
     "cfitsio": {
       "baseline": "3.49",

versions/c-/ceres.json

@@ -1,5 +1,10 @@
 {
   "versions": [
+    {
+      "git-tree": "213619bf4451443bd69f784f9a7fa32fc2436e07",
+      "version": "2.1.0",
+      "port-version": 5
+    },
     {
       "git-tree": "b2ebeb85c8833b2631210c4b790204151e402981",
       "version": "2.1.0",