Update heapless requirement from 0.8 to 0.9 in the cargo-dependencies group across 1 directory

[dependabot]

Updates the requirements on heapless to permit the latest version.
Updates heapless to 0.9.3

Release notes

Sourced from heapless's releases.

0.9.3

See the full changelog here: https://github.com/rust-embedded/heapless/blob/v0.9.3/CHANGELOG.md#v093-2025-04-15

Changelog

Sourced from heapless's changelog.

[v0.9.3] 2025-04-15

• Fixed unsoundness in Deque::clear, HistoryBuf::clear and IndexMap::clear in the context of panicking drop implementations.
• Added from_bytes_truncating_at_nul to CString
• Added CString::{into_bytes, into_bytes_with_nul, into_string}
• Added pop_front_if and pop_back_if to Deque
• Made Vec::from_array const.
• Fixed long division being instroduced by the const-erasure in spsc
• spsc: Fix integer overflow in iterators when N > usize::MAX/2 and the queue loops.
• spsc: Fix integer overflow leading to a panic in len when N == usize::MAX and debug assertions are enabled.

[v0.9.2] 2025-11-12

• Added from_bytes_truncating_at_nul to CString
• Added missing ?Sized bounds in PartialEq implementations
• Make PartialEq implementation for DequeInner and HistoryBufInner generic over the storage of the RHS
• Minor fixes to module docs.
• Make MSRV of 1.87.0 explicit.
• Implement Default for CapacityError.
• Implement defmt::Format for CapacityError.
• Implement TryFrom for Deque from array.
• Switch from serde to serde_core for enabling faster compilations.
• Implement Zeroize trait for all data structures with the zeroize feature to securely clear sensitive data from memory.
• Added truncate to Deque
• Added retain to Deque
• Added retain_mut to Deque
• Added into_raw to Box
• Added from_raw to Box
• Added FusedIterator to vec::IntoIter, deque::IntoIter, index_map::IntoIter and linear_map::IntoIter.
• Added ExactSizeIterator to vec::IntoIter, deque::IntoIter, index_map::IntoIter and linear_map::IntoIter.
• Added DoubleEndedIterator to vec::IntoIter and deque::IntoIter.
• Deprecate mpmc (see #583)
• Fixed initialization of the ArcBlock<T> and BoxBlock<T> types, fixing possible Undefined Behavior

[v0.9.1] - 2025-08-19

Added

• Added String::insert and String::insert_str.

Added

• Added optional embedded_io::Write impl for Vec.

Changed

• bytes::BufMut is now implemented on VecInner.
• Removed generic from history_buf::OldestOrdered.
• Made LenType opt-in.
• Minor fixes to pool::boxed docs.

... (truncated)

Commits

• ca95c4b Merge pull request #656 from sgued/release-093
• c3d2061 Prepare release 0.9.3
• fba1da4 Merge pull request #644 from tower120/const_vec_from_array
• 6bb5909 Fix clippy lints
• 666a0ac Vec::from_array now const
• 0db1fb3 Add IDEA files to gitignore
• be8628a Merge pull request #647 from sgued/646-clear-use-after-free
• e458255 Fix possible use after free in clear functions
• 45a1f11 Merge pull request #641 from sgued/deque-pop-front-if
• 8d95d99 deque: Add pop_front_if and pop_back_if
• Additional commits viewable in compare view