fix(auth): strip trailing slashes from OAuth metadata URLs #3154

Job	Run time
checks / docs	40s
checks / readme-snippets	16s
checks / pre-commit	53s
checks / test (3.11, lowest-direct, ubuntu-latest)	56s
checks / test (3.10, locked, ubuntu-latest)	59s
checks / test (3.12, lowest-direct, windows-latest)	1m 34s
checks / test (3.12, locked, windows-latest)	1m 34s
checks / test (3.14, lowest-direct, ubuntu-latest)	53s
checks / test (3.10, lowest-direct, ubuntu-latest)	59s
checks / test (3.10, lowest-direct, windows-latest)	1m 25s
checks / test (3.13, locked, windows-latest)	1m 17s
checks / test (3.12, lowest-direct, ubuntu-latest)	1m 3s
checks / test (3.10, locked, windows-latest)	1m 40s
checks / test (3.11, locked, ubuntu-latest)	57s
checks / test (3.11, lowest-direct, windows-latest)	1m 46s
checks / test (3.13, lowest-direct, ubuntu-latest)	58s
checks / test (3.14, lowest-direct, windows-latest)	1m 51s
checks / test (3.13, lowest-direct, windows-latest)	1m 33s
checks / test (3.13, locked, ubuntu-latest)	53s
checks / test (3.12, locked, ubuntu-latest)	1m 19s
checks / test (3.11, locked, windows-latest)	1m 43s
checks / test (3.14, locked, ubuntu-latest)	1m 57s
checks / test (3.14, locked, windows-latest)	2m 35s
all-green	5s
	29m 46s

Provide feedback