Fix `function_cache` garbage collection bug #21716

Job	Run time
build-reference-examples	1m 19s
build-sway-examples	1m 36s
build-sway-lib-core	1m 6s
build-sway-lib-std	1m 21s
get-fuel-core-version	44s
forc-fmt-check-panic	2m 12s
forc-fmt-check-sway-examples	58s
forc-fmt-check-sway-lib-core	1m 17s
forc-fmt-check-sway-lib-std	1m 2s
build-forc-doc-sway-lib-std	1m 58s
build-mdbook	4m 52s
build-forc-test-project	4m 21s
cargo-build-workspace	2m 34s
cargo-clippy	1m 0s
check-sdk-harness-test-suite-compatibility	41s
cargo-fmt-check	14s
cargo-toml-fmt-check	12s
cargo-run-e2e-test-evm	6m 26s
cargo-run-e2e-test-midenvm	6m 24s
cargo-test-forc	3m 17s
cargo-test-lib-std	4m 9s
cargo-test-sway-lsp	6m 1s
forc-pkg-fuels-deps-check	19s
forc-unit-tests	2m 5s
forc-run-benchmarks	3m 44s
cargo-test-workspace	6m 59s
cargo-unused-deps-check	4m 21s
pre-publish-check	0s
cargo-run-e2e-test-release	14m 52s
cargo-test-forc-client	4m 27s
cargo-test-forc-debug	4m 0s
cargo-run-e2e-test	14m 14s
notify-slack-on-failure	3s
build-publish-master-image	0s
publish	0s
build-publish-release-image	0s
Build and upload forc binaries to release	0s
	1h 48m 48s

Provide feedback