esp8266 Arduino - snapshot and alpha release channel

This is esp8266/Arduino described by this commit: Testing.

snapshot release (v0.0.1) which reflects git master at the specified date

alpha release (v0.0.2) which is snapshot/v0.0.1 plus all opened unmerged PR tagged with "alpha" label.

Board manager URL:
https://d-a-v.github.io/esp8266/Arduino/package_esp8266com_index.json

• version 0.0.1: git:'3.1.2-17-gb7f7b748' (Wed Jul 19 14:38:34 UTC 2023) ( )
  List of all commits since latest official release
  

• version 0.0.2: git:'3.1.2-70-g18a2cdbf' (Wed Jul 19 14:39:00 UTC 2023) ( #8958 #8899 #8873 #8845 #8828 )
  List of all commits since latest official release
  Additional PRs:
  #8958 "alpha" "optionally move float emulation code into iram"
  #8899 "alpha" "Respect timeout with SSL"
  #8873 "alpha" "Avoid large reallocations in webserver's header response"
  #8845 "alpha" "Wrappers allowing to compile and run esp32-arduino basic examples"
  #8828 "alpha" "A new approach for erasing WiFi Settings"
  not merged: #8720 "alpha" "Heap: Improve debug caller address reporting"
  not merged: #6977 "alpha" "HTTPClient: implement Stream class"