refactor: remove span based test filters (FuelLabs#4280)

## Description
closes FuelLabs#3988.

We added these span based filters as it was possible to declare
duplicate dependencies in a transitive manner and this was causing tests
to be duplicated. After the recent re-work of our module structure, it
is not possible to declare such packages anymore, so we do not need
these filters in-place.


## Checklist

- [ ] I have linked to any relevant issues.
- [ ] I have commented my code, particularly in hard-to-understand
areas.
- [ ] I have updated the documentation where relevant (API docs, the
reference, and the Sway book).
- [ ] I have added tests that prove my fix is effective or that my
feature works.
- [ ] I have added (or requested a maintainer to add) the necessary
`Breaking*` or `New Feature` labels where relevant.
- [ ] I have done my best to ensure that my PR adheres to [the Fuel Labs
Code Review
Standards](https://github.com/FuelLabs/rfcs/blob/master/text/code-standards/external-contributors.md).
- [ ] I have requested a review from the relevant team or maintainers.

Co-authored-by: Joshua Batty <[email protected]>

forc-test/src/lib.rs

@@ -1,4 +1,4 @@
-use std::{collections::HashSet, fs, path::PathBuf, sync::Arc};
+use std::{fs, path::PathBuf, sync::Arc};
 
 use forc_pkg as pkg;
 use fuel_abi_types::error_codes::ErrorSignal;
@@ -172,16 +172,13 @@ impl<'a> PackageTests {
 
     /// Run all tests for this package and collect their results.
     pub(crate) fn run_tests(&self) -> anyhow::Result<TestedPackage> {
-        // TODO: Remove this once https://github.com/FuelLabs/sway/issues/3947 is solved.
-        let mut visited_tests = HashSet::new();
         let pkg_with_tests = self.built_pkg_with_tests();
         // TODO: We can easily parallelise this, but let's wait until testing is stable first.
         let tests = pkg_with_tests
             .bytecode
             .entries
             .iter()
             .filter_map(|entry| entry.kind.test().map(|test| (entry, test)))
-            .filter(|(_, test_entry)| visited_tests.insert(&test_entry.span))
             .map(|(entry, test_entry)| {
                 let offset = u32::try_from(entry.finalized.imm)
                     .expect("test instruction offset out of range");
@@ -323,9 +320,6 @@ impl TestResult {
 impl BuiltTests {
     /// The total number of tests.
     pub fn test_count(&self) -> usize {
-        // TODO: Remove this once https://github.com/FuelLabs/sway/issues/3947 is solved.
-        let mut visited_tests = HashSet::new();
-
         let pkgs: Vec<&PackageTests> = match self {
             BuiltTests::Package(pkg) => vec![pkg],
             BuiltTests::Workspace(workspace) => workspace.iter().collect(),
@@ -337,7 +331,6 @@ impl BuiltTests {
                     .entries
                     .iter()
                     .filter_map(|entry| entry.kind.test().map(|test| (entry, test)))
-                    .filter(|(_, test_entry)| visited_tests.insert(&test_entry.span))
                     .count()
             })
             .sum()