x/oauth2: TestExchangeRequest_JSONResponse failures

[gopherbot]

#!watchflakes
default <- pkg == "golang.org/x/oauth2" && test == "TestExchangeRequest_JSONResponse"

Issue created automatically to collect these failures.

Example (log):

--- FAIL: TestExchangeRequest_JSONResponse (0.01s)
    oauth2_test.go:191: Unexpected authorization header,  is found.
    oauth2_test.go:202: Unexpected exchange payload, client_id=CLIENT_ID&client_secret=CLIENT_SECRET&code=exchange-code&grant_type=authorization_code&redirect_uri=REDIRECT_URL is found.

— watchflakes

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
default <- pkg == "golang.org/x/oauth2" && test == "TestExchangeRequest_JSONResponse"

2024-04-05 22:25 netbsd-amd64-9_3 oauth2@e11eea88 go@661f9814 x/oauth2.TestExchangeRequest_JSONResponse (log)

--- FAIL: TestExchangeRequest_JSONResponse (0.01s)
    oauth2_test.go:191: Unexpected authorization header,  is found.
    oauth2_test.go:202: Unexpected exchange payload, client_id=CLIENT_ID&client_secret=CLIENT_SECRET&code=exchange-code&grant_type=authorization_code&redirect_uri=REDIRECT_URL is found.

— watchflakes

[seankhliao]

this might be from stale auth style cache entries where httptest has chosen to reuse a port number from a different test