Change pins from `<pkg> =*=<bld>` to `<pkg> * <bld>`

[jakirkham]

The linter now recommends to reformulate pins to not use the repeated =s syntax

This would involve making changes like the following

-- libxgboost =*={{ string_prefix }}_h*_{{ PKG_BUILDNUM }}
+- libxgboost * {{ string_prefix }}_h*_{{ PKG_BUILDNUM }}

Unfortunately this causes build errors with conda-build. This may be fixed in conda-build version 25.3. Flagging to revisit once the pieces are in place

Refs:

• Use latest conda-forge Linux OS version #219 (comment)
• Removing = pins as hinted breaks grpc recipe conda-smithy#2262
• Match build strings with globs conda/conda-build#5600
• conda-build v25.3.0 conda-build-feedstock#249

[jakirkham]

Trying this should be as simple as...

• Reapplying this commit: 49fce8b
• Reverting this reversion commit:b24cfbf

[jakirkham]

Requires the resolution of issue: #233