chore(deps): consume alkcall 0.7.1; raise rust-version floor 1.85 -> 1.88

- the 1.85 claim was already false at the dependency level: the resolved
  lockfile pulls icu_* 2.x (MSRV 1.86 via jsonschema -> idna) and, since
  alkcall 0.7.1, alkcall itself declares 1.88 — 1.85 toolchains cannot
  build the tree regardless of what Cargo.toml declared
- raising the floor to 1.88 aligns with the ecosystem MSRV decision
  (noq QUIC path, per the alknet MSRV audit; recorded for alktls in
  OQ-TLS-08) and breaks no downstream that could build the crate before
- alkcall 0.7.1 rides in via the lockfile (version = "0.7" already
  covered it); no code change forced — 0.7.1 is its own MSRV raise plus
  the cf-006/cf-007 work consumed in the 0.7.0 wave
- one 1.88 clippy lint fixed: uninlined_format_args in a forward.rs test

Verification: 1.85 check fails as documented (icu_* 1.88 floors); 1.88
toolchain check/test/clippy --all-targets -D warnings clean; stable 1.94
test 456 (default) / 589 (all-features), clippy -D warnings (default +
all-features), fmt --check, doc --no-deps

src/adapters/forward.rs

@@ -2125,8 +2125,7 @@ mod tests {
                     );
                     assert!(
                         !segments.iter().any(|s| s == "." || s == ".."),
-                        "value `{value:?}` must not leave lone dot segments: {:?}",
-                        segments
+                        "value `{value:?}` must not leave lone dot segments: {segments:?}"
                     );
                 }
                 Err(err) => {