python,python3: Update host pip[3] install functions

* Add --cache-dir option to set the pip cache to a directory in
$(DL_DIR), instead of pip's default (build user's ~/.cache/pip),
fixes #9066

* Add --disable-pip-version-check option, since the version check only
prints a message saying a new version is available

* Combine host_python_pip_install and host_python_pip_install_host into
Build/Compile/HostPy[3]PipInstall

* Remove --root and --prefix options, since this function is only used
to install packages to host Python's default site-packages directory
(setting these may serve to confuse pip)

* Pass all of $(HOST_PYTHON[3]_PACKAGE_BUILD_DEPENDS) to the function,
since pip can handle multiple arguments/packages

Signed-off-by: Jeffery To <jeffery.to@gmail.com>

lang/python/python-host.mk

@@ -71,16 +71,15 @@ endef
 
 # Note: I shamelessly copied this from Yousong's logic (from python-packages);
 HOST_PYTHON_PIP:=$(STAGING_DIR_HOSTPKG)/bin/pip$(PYTHON_VERSION)
-define host_python_pip_install
-	$(call host_python_settings) \
-	$(HOST_PYTHON_PIP) install \
-		--root=$(1) \
-		--prefix=$(2) \
-		$(3)
-endef
 
-define host_python_pip_install_host
-$(call host_python_pip_install,$(STAGING_DIR_HOSTPKG),"",$(1))
+# $(1) => packages to install
+define Build/Compile/HostPyPipInstall
+	$(call host_python_settings) \
+	$(HOST_PYTHON_PIP) \
+		--disable-pip-version-check \
+		--cache-dir "$(DL_DIR)/pip-cache" \
+		install \
+		$(1)
 endef
 
 # $(1) => build subdir

lang/python/python-package.mk

@@ -121,8 +121,8 @@ PYTHON_PKG_SETUP_ARGS ?= --single-version-externally-managed
 PYTHON_PKG_SETUP_VARS ?=
 
 define PyBuild/Compile/Default
-	$(foreach pkg,$(HOST_PYTHON_PACKAGE_BUILD_DEPENDS),
-		$(call host_python_pip_install_host,$(pkg))
+	$(if $(HOST_PYTHON_PACKAGE_BUILD_DEPENDS),
+		$(call Build/Compile/HostPyPipInstall,$(HOST_PYTHON_PACKAGE_BUILD_DEPENDS))
 	)
 	$(call Build/Compile/PyMod, \
 		$(PYTHON_PKG_SETUP_DIR), \

lang/python/python3-host.mk

@@ -71,16 +71,15 @@ endef
 
 # Note: I shamelessly copied this from Yousong's logic (from python-packages);
 HOST_PYTHON3_PIP:=$(STAGING_DIR_HOSTPKG)/bin/pip$(PYTHON3_VERSION)
-define host_python3_pip_install
-	$(call host_python3_settings) \
-	$(HOST_PYTHON3_PIP) install \
-		--root=$(1) \
-		--prefix=$(2) \
-		$(3)
-endef
 
-define host_python3_pip_install_host
-$(call host_python3_pip_install,$(STAGING_DIR_HOSTPKG),"",$(1))
+# $(1) => packages to install
+define Build/Compile/HostPy3PipInstall
+	$(call host_python3_settings) \
+	$(HOST_PYTHON3_PIP) \
+		--disable-pip-version-check \
+		--cache-dir "$(DL_DIR)/pip-cache" \
+		install \
+		$(1)
 endef
 
 # $(1) => build subdir

lang/python/python3-package.mk

@@ -120,8 +120,8 @@ PYTHON3_PKG_SETUP_ARGS ?= --single-version-externally-managed
 PYTHON3_PKG_SETUP_VARS ?=
 
 define Py3Build/Compile/Default
-	$(foreach pkg,$(HOST_PYTHON3_PACKAGE_BUILD_DEPENDS),
-		$(call host_python3_pip_install_host,$(pkg))
+	$(if $(HOST_PYTHON3_PACKAGE_BUILD_DEPENDS),
+		$(call Build/Compile/HostPy3PipInstall,$(HOST_PYTHON3_PACKAGE_BUILD_DEPENDS))
 	)
 	$(call Build/Compile/Py3Mod, \
 		$(PYTHON3_PKG_SETUP_DIR), \