build: bump self version to 0.7.1

With the desire to keep RuyiSDK's press-oriented version number and
Ruyi's semver aligned, and the fact that the release is intended to fix
a user story for "RuyiSDK 0.7", let's name the release 0.7.1 (also this
version number is going to provoke some certain image in riscv devs).
This is also intended to be a test for future real patch releases.

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "ruyi"
-version = "0.7.0"
+version = "0.7.1"
 description = "Package manager for RuyiSDK"
 keywords = ["ruyi", "ruyisdk"]
 # license = { file = "LICENSE-Apache.txt" }