feat(sdk): Support refreshing the access token in Client::fetch_server_versions

[zecakeh]

We need to handle 2 possible deadlocks for this:

1. We cannot try to refresh an expired access token if this call happens
   while we are currently trying to refresh the token. The easiest way
   to handle this is to never try to refresh the token when making this
   call inside get_path_builder_input() so we implement a "failsafe"
   mode that disables refreshing the access token in case it expired.
   However it attempts the GET /versions request again without the token.
2. We cannot access the cached supported versions if we are in the
   process of refreshing that cache because the RwLock has a write lock.
   So if the access token has expired and we try to refresh it, the
   possible calls to get_path_builder_input() must not wait for a read
   lock to be available. So the solution is to never wait for a read
   lock, and skip the cache if a read lock is not available.

This also gets rid of workarounds in other functions.

[codecov]

Codecov Report

❌ Patch coverage is 90.85366% with 15 lines in your changes missing coverage. Please review.
✅ Project coverage is 88.65%. Comparing base (ab98028) to head (564e652).
⚠️ Report is 6 commits behind head on main.
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
crates/matrix-sdk/src/client/mod.rs	94.87%	1 Missing and 3 partials ⚠️
crates/matrix-sdk/src/authentication/oauth/mod.rs	70.00%	1 Missing and 2 partials ⚠️
crates/matrix-sdk/src/http_client/mod.rs	72.72%	2 Missing and 1 partial ⚠️
crates/matrix-sdk/src/test_utils/mocks/mod.rs	91.17%	2 Missing and 1 partial ⚠️
crates/matrix-sdk/src/authentication/mod.rs	93.33%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5916      +/-   ##
==========================================
- Coverage   88.66%   88.65%   -0.01%     
==========================================
  Files         363      363              
  Lines      104579   104690     +111     
  Branches   104579   104690     +111     
==========================================
+ Hits        92726    92818      +92     
- Misses       7505     7518      +13     
- Partials     4348     4354       +6     

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[codspeed-hq]

CodSpeed Performance Report

Merging #5916 will not alter performance

_{Comparing zecakeh:expired-access-token (564e652) with main (9f02dcd)}

Summary

✅ 50 untouched

[andybalaam]

Very clear, thanks.