Merge bitcoin/bitcoin#32943: depends: Force CMAKE_EXPORT_NO_PACKAGE_REGISTRY=TRUE

44f3bae depends: Force `CMAKE_EXPORT_NO_PACKAGE_REGISTRY=TRUE` (Hennadii Stepanov)

Pull request description:

  When using CMake policies 3.14 and below, the `export(PACKAGE)` command by default populates the user package registry, which is stored outside the build tree. Setting the `CMAKE_EXPORT_NO_PACKAGE_REGISTRY` variable disables this side effect.

  In CMake 3.15 and later, this behavior is disabled by default, and the variable has no effect.

  This PR forces `CMAKE_EXPORT_NO_PACKAGE_REGISTRY=TRUE` globally, rather than managing it for each dependency package individually rather. It may be reverted once all CMake-based packages have updated to policies 3.15 or newer.

  Fixes bitcoin/bitcoin#32938.

ACKs for top commit:
  fanquake:
    ACK 44f3bae

Tree-SHA512: 0aac398b7182e80185b064d59f81aece4d8477a609fad9cc3fee317da2aff43b66ef7db1efec0135b4f0feaad23b1db664e33bd035fe659712c5b2a9bf2d6fb6

Author: fanquake

depends/funcs.mk

@@ -224,6 +224,7 @@ $(1)_cmake=env CC="$$($(1)_cc)" \
                -DCMAKE_INSTALL_LIBDIR=lib/ \
                -DCMAKE_POSITION_INDEPENDENT_CODE=ON \
                -DCMAKE_VERBOSE_MAKEFILE:BOOL=$(V) \
+               -DCMAKE_EXPORT_NO_PACKAGE_REGISTRY:BOOL=TRUE \
                $$($(1)_config_opts)
 ifeq ($($(1)_type),build)
 $(1)_cmake += -DCMAKE_INSTALL_RPATH:PATH="$$($($(1)_type)_prefix)/lib"