[motus] address review feedback

vcpkg_check_linkage(ONLY_STATIC_LIBRARY), since upstream declares
add_library(motus STATIC ...) unconditionally.

Dropped the custom usage file, which only restated the usage text vcpkg
generates from the installed CMake config.

Added -DCMAKE_DISABLE_FIND_PACKAGE_Git=ON. This stops v1.0.0's provenance
lookup from recording vcpkg's own commit as motus provenance, which is the
issue found in review, and it makes Git a port-controlled optional dependency.
Upstream has since bounded that lookup to its own worktree, so a future release
will not need the flag for correctness, only for control.

Removed the SHA512 comment.

Version database updated for the new port tree.

ports/motus/portfile.cmake

@@ -1,7 +1,4 @@
-# vcpkg port for motus.
-#
-# The SHA512 below is the checksum of the v1.0.0 source archive; recompute for any new REF
-# with `vcpkg hash <tarball>` (the SUBMITTING.md beside this port has the exact command).
+vcpkg_check_linkage(ONLY_STATIC_LIBRARY)
 
 vcpkg_from_github(
     OUT_SOURCE_PATH SOURCE_PATH
@@ -18,11 +15,18 @@ vcpkg_cmake_configure(
         -DMOTUS_WITH_AMQPCPP=ON
         -DMOTUS_WITH_INMEMORY=ON
         -DMOTUS_WITH_SIMPLEAMQP=OFF
+        # Git is an optional build dependency upstream, used only to stamp a build identity
+        # into the generated Version.hpp. In v1.0.0 that lookup runs `git rev-parse HEAD`
+        # without confirming the source directory is the worktree root, so under vcpkg it
+        # walked up and reported vcpkg's own commit as motus provenance. Upstream now bounds
+        # the lookup to its own worktree; until a release carries that fix, denying the
+        # package outright is what keeps the build honest, and it makes the dependency
+        # controlled by the port rather than by whatever happens to be on the machine.
+        -DCMAKE_DISABLE_FIND_PACKAGE_Git=ON
 )
 
 vcpkg_cmake_install()
 vcpkg_cmake_config_fixup(CONFIG_PATH "lib/cmake/motus")
-file(INSTALL "${CMAKE_CURRENT_LIST_DIR}/usage" DESTINATION "${CURRENT_PACKAGES_DIR}/share/${PORT}")
 vcpkg_copy_pdbs()
 
 file(REMOVE_RECURSE "${CURRENT_PACKAGES_DIR}/debug/include")

ports/motus/usage

@@ -1,4 +0,0 @@
-motus provides CMake targets:
-
-    find_package(motus CONFIG REQUIRED)
-    target_link_libraries(main PRIVATE motus::motus)

versions/m-/motus.json

@@ -1,7 +1,7 @@
 {
   "versions": [
     {
-      "git-tree": "787e9b92eaf7eb013b7086e67113986ab785b136",
+      "git-tree": "831105d59fa4b2df73e1d1700435dbf975e86b4a",
       "version": "1.0.0",
       "port-version": 0
     }