revert(3p/git): Revert merge of git upstream at v2.26.2

This causes cgit to serve error pages, which is undesirable.

This reverts commit 5229c9b232, reversing
changes made to f2b211131f.

third_party/git/t/t5601-clone.sh

@@ -434,6 +434,7 @@ test_expect_success 'double quoted plink.exe in GIT_SSH_COMMAND' '
 	expect_ssh "-v -P 123" myhost src
 '
 
+SQ="'"
 test_expect_success 'single quoted plink.exe in GIT_SSH_COMMAND' '
 	copy_ssh_wrapper_as "$TRASH_DIRECTORY/plink.exe" &&
 	GIT_SSH_COMMAND="$SQ$TRASH_DIRECTORY/plink.exe$SQ -v" \
@@ -635,10 +636,10 @@ partial_clone_server () {
 	rm -rf "$SERVER" client &&
 	test_create_repo "$SERVER" &&
 	test_commit -C "$SERVER" one &&
-	HASH1=$(git -C "$SERVER" hash-object one.t) &&
+	HASH1=$(git hash-object "$SERVER/one.t") &&
 	git -C "$SERVER" revert HEAD &&
 	test_commit -C "$SERVER" two &&
-	HASH2=$(git -C "$SERVER" hash-object two.t) &&
+	HASH2=$(git hash-object "$SERVER/two.t") &&
 	test_config -C "$SERVER" uploadpack.allowfilter 1 &&
 	test_config -C "$SERVER" uploadpack.allowanysha1inwant 1
 }
@@ -653,8 +654,7 @@ partial_clone () {
 	git -C client fsck &&
 
 	# Ensure that unneeded blobs are not inadvertently fetched.
-	test_config -C client remote.origin.promisor "false" &&
-	git -C client config --unset remote.origin.partialclonefilter &&
+	test_config -C client extensions.partialclone "not a remote" &&
 	test_must_fail git -C client cat-file -e "$HASH1" &&
 
 	# But this blob was fetched, because clone performs an initial checkout
@@ -739,7 +739,4 @@ test_expect_success 'partial clone using HTTP' '
 	partial_clone "$HTTPD_DOCUMENT_ROOT_PATH/server" "$HTTPD_URL/smart/server"
 '
 
-# DO NOT add non-httpd-specific tests here, because the last part of this
-# test script is only executed when httpd is available and enabled.
-
 test_done