Prepare and check test env during CI (#17725)

This PR should resolve the permission problems during CI, if the uid doesn't match, a more clear message is shown.

*  CI fails with unknown permission problems #17710

The new drone step dependencies:

(root)prepare-test-env -> (gitea)build -> (gitea)test

build/test-env-check.sh

@@ -0,0 +1,24 @@
+#!/bin/sh
+
+set -e
+
+if [ ! -f ./build/test-env-check.sh ]; then
+  echo "${0} can only be executed in gitea source root directory"
+  exit 1
+fi
+
+
+echo "check uid ..."
+
+# the uid of gitea defined in "https://gitea.com/gitea/test-env" is 1000
+gitea_uid=$(id -u gitea)
+if [ "$gitea_uid" != "1000" ]; then
+  echo "The uid of linux user 'gitea' is expected to be 1000, but it is $gitea_uid"
+  exit 1
+fi
+
+cur_uid=$(id -u)
+if [ "$cur_uid" != "0" -a "$cur_uid" != "$gitea_uid" ]; then
+  echo "The uid of current linux user is expected to be 0 or $gitea_uid, but it is $cur_uid"
+  exit 1
+fi

build/test-env-prepare.sh

@@ -0,0 +1,11 @@
+#!/bin/sh
+
+set -e
+
+if [ ! -f ./build/test-env-prepare.sh ]; then
+  echo "${0} can only be executed in gitea source root directory"
+  exit 1
+fi
+
+echo "change the owner of files to gitea ..."
+chown -R gitea:gitea .