Fix arrow libraries from download & build not being found in some cas…

…es (#5366)

### What

Apparently they don't always end up in `/lib` depending on how cmake was
configured. This should fix this!

### Checklist
* [x] I have read and agree to [Contributor
Guide](https://github.com/rerun-io/rerun/blob/main/CONTRIBUTING.md) and
the [Code of
Conduct](https://github.com/rerun-io/rerun/blob/main/CODE_OF_CONDUCT.md)
* [x] I've included a screenshot or gif (if applicable)
* [x] I have tested the web demo (if applicable):
* Using newly built examples:
[app.rerun.io](https://app.rerun.io/pr/5366/index.html)
* Using examples from latest `main` build:
[app.rerun.io](https://app.rerun.io/pr/5366/index.html?manifest_url=https://app.rerun.io/version/main/examples_manifest.json)
* Using full set of examples from `nightly` build:
[app.rerun.io](https://app.rerun.io/pr/5366/index.html?manifest_url=https://app.rerun.io/version/nightly/examples_manifest.json)
* [x] The PR title and labels are set such as to maximize their
usefulness for the next release's CHANGELOG
* [x] If applicable, add a new check to the [release
checklist](https://github.com/rerun-io/rerun/blob/main/tests/python/release_checklist)!

- [PR Build Summary](https://build.rerun.io/pr/5366)
- [Docs
preview](https://rerun.io/preview/81bd42b2125820499614687246906beac4ef8e91/docs)
<!--DOCS-PREVIEW-->
- [Examples
preview](https://rerun.io/preview/81bd42b2125820499614687246906beac4ef8e91/examples)
<!--EXAMPLES-PREVIEW-->
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.github/workflows/on_pull_request.yml

@@ -53,6 +53,7 @@ jobs:
               - '**/*.hpp'
               - '**/*.cpp'
               - '**/CMakeLists.txt'
+              - '**/*cmake'
 
   rust-checks:
     name: "Rust Checks"

rerun_cpp/download_and_build_arrow.cmake

@@ -7,16 +7,19 @@ function(download_and_build_arrow)
 
     set(ARROW_DOWNLOAD_PATH ${CMAKE_BINARY_DIR}/arrow)
 
+    set(ARROW_LIB_PATH ${ARROW_DOWNLOAD_PATH}/lib)
+    set(ARROW_BIN_PATH ${ARROW_DOWNLOAD_PATH}/bin)
+
     if(RERUN_ARROW_LINK_SHARED)
         set(ARROW_BUILD_SHARED ON)
         set(ARROW_BUILD_STATIC OFF)
 
         if(APPLE)
-            set(ARROW_LIBRARY_FILE ${ARROW_DOWNLOAD_PATH}/lib/libarrow.dylib)
+            set(ARROW_LIBRARY_FILE ${ARROW_LIB_PATH}/libarrow.dylib)
         elseif(UNIX) # if(LINUX) # CMake 3.25
-            set(ARROW_LIBRARY_FILE ${ARROW_DOWNLOAD_PATH}/lib/libarrow.so)
+            set(ARROW_LIBRARY_FILE ${ARROW_LIB_PATH}/libarrow.so)
         elseif(WIN32)
-            set(ARROW_LIBRARY_FILE ${ARROW_DOWNLOAD_PATH}/bin/arrow.dll)
+            set(ARROW_LIBRARY_FILE ${ARROW_BIN_PATH}/arrow.dll)
         else()
             message(FATAL_ERROR "Unsupported platform.")
         endif()
@@ -25,14 +28,14 @@ function(download_and_build_arrow)
         set(ARROW_BUILD_STATIC ON)
 
         if(APPLE)
-            set(ARROW_LIBRARY_FILE ${ARROW_DOWNLOAD_PATH}/lib/libarrow.a)
+            set(ARROW_LIBRARY_FILE ${ARROW_LIB_PATH}/libarrow.a)
             set(ARROW_BUNDLED_DEPENDENCIES_FILE ${ARROW_DOWNLOAD_PATH}/lib/libarrow_bundled_dependencies.a)
         elseif(UNIX) # if(LINUX) # CMake 3.25
-            set(ARROW_LIBRARY_FILE ${ARROW_DOWNLOAD_PATH}/lib/libarrow.a)
-            set(ARROW_BUNDLED_DEPENDENCIES_FILE ${ARROW_DOWNLOAD_PATH}/lib/libarrow_bundled_dependencies.a)
+            set(ARROW_LIBRARY_FILE ${ARROW_LIB_PATH}/libarrow.a)
+            set(ARROW_BUNDLED_DEPENDENCIES_FILE ${ARROW_LIB_PATH}/libarrow_bundled_dependencies.a)
         elseif(WIN32)
-            set(ARROW_LIBRARY_FILE ${ARROW_DOWNLOAD_PATH}/lib/arrow_static.lib)
-            set(ARROW_BUNDLED_DEPENDENCIES_FILE ${ARROW_DOWNLOAD_PATH}/lib/arrow_bundled_dependencies.lib)
+            set(ARROW_LIBRARY_FILE ${ARROW_LIB_PATH}/arrow_static.lib)
+            set(ARROW_BUNDLED_DEPENDENCIES_FILE ${ARROW_LIB_PATH}/arrow_bundled_dependencies.lib)
         else()
             message(FATAL_ERROR "Unsupported platform.")
         endif()
@@ -92,6 +95,8 @@ function(download_and_build_arrow)
         -DARROW_USE_UBSAN=OFF
         -DBOOST_SOURCE=BUNDLED
         -DCMAKE_INSTALL_PREFIX=${ARROW_DOWNLOAD_PATH}
+        -DCMAKE_INSTALL_LIBDIR=lib
+        -DCMAKE_INSTALL_BINDIR=bin
         -Dxsimd_SOURCE=BUNDLED
         -DBOOST_SOURCE=BUNDLED
         -DARROW_BOOST_USE_SHARED=OFF